Pardon me for butting in, but two passages come to mind - based on your position.
The first concerns wisdom and the contrast between what a man thinks makes sense and what God thinks.
Where is the one who is wise? Where is the scribe? Where is the debater of this age? Has not God made foolish the wisdom of the world? ... but we preach Christ crucified, a stumbling block to Jews and folly to Gentiles, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God. For the foolishness of God is wiser than men, and the weakness of God is stronger than men.
The natural person does not accept the things of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned. 15 The spiritual person judges all things, but is himself to be judged by no one. “For who has understood the mind of the Lord so as to instruct him?” But we have the mind of Christ.
1 Cor 1:20,23-25,2:14-16
Pardon me, still, but the second passage deals with our works contrasted with God's grace.
O foolish Galatians! Who has bewitched you?
For if a law had been given that could give life, then righteousness would indeed be by the law. But the Scripture imprisoned everything under sin, so that the promise by faith in Jesus Christ might be given to those who believe. Now before faith came, we were held captive under the law, imprisoned until the coming faith would be revealed. So then, the law was our guardian until Christ came, in order that we might be justified by faith. But now that faith has come, we are no longer under a guardian, for in Christ Jesus you are all sons of God, through faith.
Galatians 3:1,21-26
I left out a lot of valuable verses... very valuable... I didn't want to lose your attention. Please read and understand.
Bonus verse (that just came to mind and is apropos):
For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them. Ephesians 2:8-10
You also might want to look through Romans 7 - just to see what is said about the sins of an evidently saved man.
Your doubt of eternal security is evident but God's own words should have already laid that concern to rest.
It really comes down to this: Do you trust the whole counsel of God or are you depending on individual bits, taken without context and the traditions handed down by your fathers?
Thank you for your attention.
The first concerns wisdom and the contrast between what a man thinks makes sense and what God thinks.
Concerning wisdom...man vs. God
Psalms 111:
7The works of his hands are verity and judgment; all his commandments are sure. 8They stand fast for ever and ever, and are done in truth and uprightness. 9He sent redemption unto his people: he hath commanded his covenant for ever: holy and reverend is his name. 10The fear of the LORD is the beginning of wisdom: a good understanding have all they that do his commandments: his praise endureth for ever.