[This is a cannibalized section from the eschatology section from my systematic theology book, about the importance of the baptism of the spirit.]
“You will know them by their fruits. Are grapes gathered from thorn bushes or figs from thistles?
17 Even so, every good tree bears good fruit, but the bad tree bears bad fruit.
18 A good tree cannot bear bad fruit, nor can a bad tree bear good fruit,”
(Matt. 7-16-18 LSB).
“But whoever speaks against the Holy Spirit, it will not be forgiven him either in this age or in the coming one!
33 “Either make the tree good and its fruit is good, or make the tree bad and its fruit is bad, for the tree is known by its fruit.
34 Offspring of vipers! How are you able to say good things when you[q] are evil,”
(Matt 12:32-34 LEB).
“For there is no good tree that produces bad fruit, nor on the other hand a bad tree that produces good fruit, 44 for each tree is known by its own fruit. For figs are not gathered from thorn plants, nor are grapes harvested from thorn bushes. 45 The good person out of the good treasury of his heart brings forth good, and the evil person out of his evil treasure brings forth evil. For out of the abundance of the heart his mouth speaks,” (Luke 6:43-45 LEB).
Jesus puts a focus on bad words and bad doctrine in how He defines bad fruit, because the context is the Jewish leaders committing the blaspheme of the Holy Spirit with a false doctrine that affirmed the works of the Spirit come from Satan. In Matthew 7 this is said in context of obeying God’s law and Jesus showing the true standard God commands, and thus, this is a universal teaching on all obedience and disobedience to God’s commandments. So, although bad fruit is a universal category for all disobedience, Jesus does put a stronger focus on disobedience with affirming false doctrine. Jesus says, “how can you SAY good things, when you are evil.” This statement contradicts Jesus’ truth claims about reality; thus, they cannot say good things, because they are evil, and they are evil and so they say evil things.
In Matthew 7:17-18 Jesus makes 4 truth claims. We will put them from A to D. Since Jesus intends for us to add ourselves or someone else to this, and thus we have 3 terms and a deductive application. We will use hypothetical syllogisms for simplicity with modus tollens, rather than categorical syllogisms and contrapositions, which can be a little more difficult (for understanding why and how) for those who have not studied logic. Example, the contraposition for, “all [good trees] are [good fruit bearers],” in the defined context of Jesus’ truth claims, would be “all [bad fruit bearers] are [bad trees].” In natural deduction this rule is transposition or contraposition.
A, If good tree, then good fruit.
B, If bad tree, then bad fruit.
C, If good tree, then no bad fruit.
D, If bad tree, then no good fruit.
Jesus is repeating Himself in premise C and D, because their logical conclusions in Modus Tollens are the same for A and B.
In essence, with premise A and B, with the uses of Modus ponens and Modus tollens, we have 4 deductive conclusion or outputs.
Jesus defines the context in a way that these are opposites, and that there is no other options. When it comes to person and the law of God, there is obedience or disobedience; there is no other option. When it comes to a person and being born again in spiritual life or under spiritual death, there is no other options. Therefore, the negation will be said as “bad fruit or tree,” or “good fruit or tree,” since in context this is what the negation is.
If we only had premise “A” and we did a Modus ponens and tollens (or in categorical contraposition), then we can say “because bad fruit, thus bad tree,” but not, “because good fruit thus, good trees.” However, with premise B, and then with Jesus’ further restating this doctrine in premise C and D, we have the latter conclusion. Also, C and D close off any overlap for the categories of obedience (good fruit) and disobedience (bad fruit) for humans.
A.1.(P) If good tree, (Q) then good fruit.
A.2. (P). Good tree
A.3. Thus, (Q) good fruit
Then the Modus Tollens, Ab.
Ab.1. (P) If good tree, (Q) then good fruit.
Ab.2. ~(Q) bad fruit.
Ab.3. Thus, ~(P) bad tree.
B.1. (P) If bad tree, (P) then bad fruit.
B.2. (P). Bad Tree.
B.3. Thus, (Q) bad fruit.
Then the Modus Tollens, Bb.
Bb.1. (P) If bad tree, (P) then bad fruit.
Bb.2. ~(Q) Good fruit.
Bb.3. Thus ~(P) Good tree.
When Jesus says, “you will know them by their fruit,” it is being used as a proof. Jesus is saying, “x” proves that there is “y.” By using the Modus tollens we see bad fruit does prove bad tree, and good fruit proves a good tree. This can sometimes be seen with past, present and future tense verbs. As a category statement, “A good tree DOES or WILL produce good fruit.” Using the logic of double negative in reverse order, “if you produce bad fruit, then you have been or are a bad tree.”
The positive statements are positive statements about “metaphysics.” They are what God has created and sovereignly caused. The modus tollens, are being used as a way for us to discover and “prove” what metaphysics God as put us into, through our obedience or disobedience.
These statements of Jesus are universal; they are all encompassing statements about all good works in obedience and all bad works in disobedience. Jesus takes a few words from the Jewish leaders and says, “this specific bad fruit of false doctrine you said, is proof you are a bad tree.” Thus, applying this knowledge in deduction, any biblical premise that narrowly speaks of one type of bad or good fruit, even if only mentioned in one premise, applies to all four possible combinations shown. Whether it is John in “1st John,” talking about the good or bad fruit of loving God or loving your brother, it applies to all 4 combinations. “The one who hates his brother is in the darkness,” (1 John 2:11 LEB).
The same with Jesus saying,
“7 If you remain in me and my words remain in you, ask whatever you want and it will be done for you. 8 My Father is glorified by this: that you bear much fruit, and prove to be my disciples… 16 You did not choose me, but I chose you and appointed you that you should go and bear fruit, and your fruit should remain, in order that whatever you ask the Father in my name he will give you. 17 These things I command you.”
Vincent Cheung has a great essay on this called, “Predestination and Miracles.”
God has chosen us, and predestined us. Predestined for what? There was more to what Jesus said: “You did not choose me, but I chose you and appointed you to go and bear fruit — fruit that will last. Then the Father will give you whatever you ask in my name.” God predestined us to bear fruit. What is this fruit? Christian teaching often assumes that fruit refers to spiritual and ethical effects such as improvements in character, works of charity, and also works of ministry, such as saving sinners and building churches. This is not entirely wrong, but the biblical idea of fruit includes much more, and Jesus clearly had other things in mind when he made the statement.
Even in the same verse, we can see that Jesus had in mind not only works of preaching and charity, because he said his followers would produce fruit and that “the Father will give you whatever you ask in my name.” Gospel life and ministry is characterized by answers to prayers. What kinds of prayers? Wait, this is weaker than the way Jesus said it. The doctrine of prayer in historic unbelief is that “God will answer your prayers if it is his will (regardless of what he promised). Or, you can say that he always answers your prayers — sometimes he says yes, sometimes no, sometimes maybe, sometimes later. Or, when you ask for egg, he will give you a scorpion, so that when you ask for spiritual growth, he will give you cancer to teach you a lesson.” Among us, we have never accepted this view of prayer. We recognize it as satanic deception. But Jesus did not even say, “God will answer your prayers” or “God will always answer your prayers.” He said, “God will give you whatever you ask.” This is how God wants us to think about our relationship with him. This is how he wants us to think about discipleship. This is how he wants us to think about faith and prayer. God will give me whatever I ask when I approach him in the name of Jesus. No hiding behind a thousand qualifications. No excuses for me or for him.
God will give me whatever I ask. I will have whatever I ask. What I ask, I get. And I am predestined for this. So I am chosen to get whatever I ask. I am predestined to get whatever I ask. It is my foreordained destiny to receive whatever I ask God in the name of Jesus. If you have never heard this, then you have never heard the Bible’s doctrine of predestination, you have never heard the Bible’s doctrine of prayer, you have never heard the Bible’s doctrine of the name of Jesus, and you have never heard the Bible’s doctrine of discipleship. Just several verses earlier, Jesus said, “If you remain in me and my words remain in you, ask whatever you wish, and it will be given you. This is to my Father’s glory, that you bear much fruit, showing yourselves to be my disciples” (15:7-8). Getting whatever we ask from God is intertwined throughout his discourse with the notions of bearing fruit, being his disciples, and loving one another. Thus getting whatever we ask from God is as pervasive as the gospel itself. It cannot be taken out and thrown away without tearing apart the entire gospel, and thus also our salvation. Here bearing fruit is almost the same thing as getting whatever we ask from God, and by getting what we ask from God, we show ourselves to be true disciples of Christ.
The metaphysics that God sovereignly causes, is that a disciple (good tree), produces the (good fruit) of asking and receiving what they ask for.
Jesus defines good fruit as obeying His commandments. His command here, is to disciples (not merely apostles) to pray and get what you pray for. You need to think about that. It is a command from your God; it is not a mere suggestion or self-help tip. Jesus has already defined good and bad people by obedience and disobedience with 4 possible combinations, and thus, the same applies here. Bad fruit is praying and not receiving what you pray for. Thus, if you pray and do not receive because you lack faith, you are producing bad fruit. A continued life of this bad fruit is proof you are not His good disciple. A continued life of this bad fruit is proof Jesus did not predestine or appoint you to bear good fruit. It proves you were chosen by God to be a reprobate.
The apostles said, “then God has granted them repentance to life.” God’s sovereign work caused and predestined these with spiritual life (born from above) and reconciled them to Him, by repentance (faith). It is a statement of metaphysics; they are saved; they live in Spiritual life now; they live reconciled to God. When applied for good or bad fruit, it is the same as has been demonstrated, it is a test of proof.
The same is for baptism of the Spirit. If baptism of the Spirit (good fruit), then proof of the metaphysics that you are did repent and are in the category of spiritual “life” and “saved,” (good tree). Bad fruit is not being baptized in the Spirit. A continued rebellion and disobedience in not being baptized in the Spirit is proof of reprobation, especially in context of doctrine. If you continue in affirming the false doctrines that God does not command you to love your brother, and that Jesus did not teach that truth does set you free, and Jesus did not teach that you get what you ask for in faith, and that God does not command you to be baptism in the Spirit, then you give strong proof you are a reprobate. If continued affirmation of false doctrine on this doctrine is not repented of, then stronger proof of God’s predestination of your reprobation. The same for hating your brother, (etc.). Hebrews 12 affirms that Christians have besetting sin. “let us lay aside the sins that easily entangle us.” It does happen. But the same chapter says to look to Jesus who is the author and “perfecter” of our faith. We are told to get free. We are told Jesus is able to heal dislocated shoulders. The great danger is not repenting and being arrogant. To be arrogant and unrepentance in continued false doctrine is a great, if not the greatest danger of proof for reprobation. Jesus was very compassionate with those who were at least trying to repent and follow, “lord help my unbelief.” Paul, after correcting the Corinthians for many sinful actions, kept encouraging them to repent and get better. At the end of the letter, he says to double check and make sure your election is sure. If no repentance of your bad fruit, then you give proof of reprobation. For the false teachers that Paul dealt with, he didn’t record that even prayed for God to save them, but says regarding the coppersmith that God would “repay him” for the harm of the false doctrine and unbelief he was spreading. Likewise Paul says in Philippians 4 the women and Clement’s names are in the “book of life (v.3),” because of their labor in the gospel. That is, Paul says their election of being saints is certain, because of their good fruit, and not because Paul received a divine revelation about them. We can do the same. Jude, regarding the false teachers, says they are reprobates destined for hell with the demons. However, regarding the Corinthians who were not affirming false doctrines as false teachers, but sinning in sins of passion, Paul corrected them and told them that “temples of God” do not behave that way.
We will now examine these arguments by putting them into syllogism A and B from above, since these two alone will output all the combinations we need.
Love and hating your brother.
A.1.(P) If born from above, (Q) then love for your brother.
A.2. (P). Born from above.
A.3. Thus, (Q) Love for your brother.
Then the Modus Tollens, Ab.
Ab.1. (P) If born from above, (Q) then love for your brother.
Ab.2. ~(Q) hates your brother.
Ab.3. Thus, ~(P) proof of being born from below.
B.1. (P) If born from below, (P) then hates your brother.
B.2. (P). Born from below.
B.3. Thus, (Q) hates your brother.
Then the Modus Tollens, Bb.
Bb.1. (P) If born from below, (P) then hates your brother.
Bb.2. ~(Q) loves your brother.
Bb.3. Thus ~(P) proof of being born from above.
Ask and get what You pray for.
A.1.(P) If good disciple, (Q) then ask and get what you ask for.
A.2. (P). Good disciple.
A.3. Thus, (Q) ask and get what you ask for.
Then the Modus Tollens, Ab.
Ab.1. (P) If good disciple, (Q) then ask and get what you ask for.
Ab.2. ~(Q) ask and not get what you ask for.
Ab.3. Thus, ~(P) proof of bad disciple.
B.1. (P) If bad disciple, (P) then ask and not get what you ask for.
B.2. (P). Bad disciple.
B.3. Thus, (Q) ask and not get what you ask for.
Then the Modus Tollens, Bb.
Bb.1. (P) If bad disciple, (P) then ask and not get what you ask for.
Bb.2. ~(Q) ask and get what you ask for.
Bb.3. Thus ~(P) proof of good disciple.
Baptism of the Spirit.
Peter and the apostles defined the “good tree” as repentance to be “saved,” and repentance of “life.” Thus the metaphysical category is life and saved. We will call this saved and unsaved.
A.1.(P) If saved, (Q) then baptism of Spirit.
A.2. (P) saved.
A.3. Thus, (Q) baptism of the Spirit.
Then the Modus Tollens, Ab.
Ab.1. (P) If saved, (Q) then baptism of the Spirit.
Ab.2. ~(Q) no baptism in the Spirit.
Ab.3. Thus, ~(P) no proof of being saved.
B.1. (P) If unsaved, (P) then no baptism of the Spirit.
B.2. (P) unsaved.
B.3. Thus, (Q) no baptism of the Spirit.
Then the Modus Tollens, Bb.
Bb.1. (P) If unsaved, (P) then no baptism of the Spirit.
Bb.2. ~(Q) baptism of Spirit.
Bb.3. Thus ~(P) thus proof for being saved.
 That is, without context, as you might find in a logic textbook, you would need to say, “all [non-good fruit bearers] are [non-good trees].” However, unlike a logic book, that mostly gives the absolute minimum context of something, in Christianity we have a substantial context of knowledge about the world. We know exactly what Jesus means by “non-good trees” for humans commanded to obey His words, they are “bad trees.”
 I have seen some morons in modern logic want to deny the “law of excluded middle,” which is what makes this reverse double negative logic work. Aside from all rules showing this to be valid, included truth tables, it is interesting that those denying this are liberal theologians and atheist and empiricists who do not have an epistemology that is able give them truth in the first place. With a necessary epistemology that gives substantial knowledge about the world, with clearly defined categories, then the law of excluded middle is valid, strong and absolute. But beside all this, Jesus and the Bible assumes the law of excluded middle. Do not let those who do not have truth to begin with, be your teachers. Leave them alone to wonder in their own delusions.
 Emphasis by author.
 Vincent Cheung. Predestination and Miracles. From the ebook, TRACE. 2018. Pg. 73-74