QUEST.. ” How to distinguish faith from feelings of certainty –how about in light of besetting sins?”
ANS. .This is a point more about epistemology and assenting. For those born again they are a new creation with a soul bent toward God through the life giving Holy Spirit. However, we are not in heaven yet. Thus, the Bible says in Galatians that the flesh wars against the Spirit and the Spirit wars against the flesh. This means that the emotion of the soul will be up and down. A mature Christian will be more even hearted in joy in God, but not perfect.
The point is how to get to this mature point of the soul. One does this by a mature faith. How do you have a mature faith? “Faith comes by hearing the Word of God.”
Now, in the fight to get there, there needs to be both a turning away from the negative/false something and then a turning to a positive/truth something. A battle with feelings is a matter of epistemology. You need to turn away from sinfully resting on false epistemologies (and the frank reality is) many Christians—without knowing it, rest on their feelings in a epistemology type way. Feelings give no truth. They give no terms of subject or terms of predicates. They are not logic; and thus, feelings are not a structure of thoughts. Rather you must presuppose or use God’s revelation in order to even understand what a feeling is. Thus, they do not even give you knowledge of yourself! They give you no knowledge about the world. Rebuke yourself for doing so. I do this to myself.
A feeling of fear over a besetting sin does not give you knowledge that you will therefore never overcome it. An experience of falling 1000 times does not give you the knowledge that you cannot overcome it. Only God’s Word gives us knowledge about the world we live in. If you “feel” fear over a besetting sin you just committed and say secretly in your heart, “I will never overcome this,” you are in practical purposes acting like an atheist, because you are concluding reality off your inductive/subjective experiences and trampling them over God’s Word. Yet only God’s Word gives a correct and precise description of reality. In epistemology you are a dualist if you do this, at best.
Feelings and experience give no knowledge about the world, only God’s Word.
So then, if you find your heart doing this rebuke yourself and then do the second positive thing. Turn “to” the promises of God. Turn to them day and night and let nothing in this world hinder you in doing so. Hebrews 12 says we will face besetting sins, but Jesus who is the author of our faith says, ”cheer up for I have defeated the world.” & “We are more than conquerors through Christ who loved us.” He has given us no temptation that He has not provided away out. If you need wisdom for fighting, then ask for wisdom from the Father of lights and He will give wisdom to you liberally. If you ask for a fish from God your Father, then your Father will give you a fish for a fish and not something else. That is, if you ask for deliverance from a sin, or for healing from a pain, then He will give a deliverance for a deliverance and a healing for a healing. Say with Joshua and say with the New Testament believers in Hebrews ch.13 who take Joshua’s promise for themselves, “God will never leave me,” and “God is my help, who can be against me.” I am a new creation and the righteousness of God in Christ; indeed, I am child of Abraham by Christ and therefore an heir of the blessing of Abraham to receive miracles and the Holy Spirit (Gal. ch.3).