The answer DHC provided in post #285 above shows from scripture how we overcome.
This physical life we go through is a wilderness experience similar to what the Jews went through when they left Egypt. And many of them did not make it to the promised land. Why? Because of unbelief.
Note Heb 3:12-19
Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God. But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. (unbelief)
For we are made partakers of Christ, if we hold the beginning of our confidence (believing in Jesus) stedfast unto the end;
While it is said, To day if ye will hear his voice, harden not your hearts, as in the provocation.
For some, when they had heard, did provoke: howbeit not all that came out of Egypt by Moses.
But with whom was he grieved forty years? was it not with them that had sinned, whose carcases fell in the wilderness?
And to whom sware he that they should not enter into his rest, but to them that believed not?
So we see that they could not enter in because of unbelief.
The sin that the world is convicted of is the sin of unbelief, John 16:9.
Unbelief includes turning back to being under the law, and there are many warnings in scripture against doing this. "To day if ye will hear his voice, harden not your hearts, as in the provocation." We should not be provoking God as the Jews did in the wilderness.
That is why God even says we should not even fellowship with those who preach the law. We should put away such wicked persons, 1 Cor 5:9, 11, 13
Remember, only "a little leaven (doctrine of works of the law, Matt 16:12) leavens the whole lump" .
We overcome the world when we believe in Jesus, 1 John 5:4, 5When we believe in Jesus we're made partakers of him, Heb 3:14
Hence we "exhort one another daily" to remain stedfast in believing in Jesus.
2 Cor 5:7 I]"For we walk by faith, not by sight"
[/I]This walk of faith is believing in Jesus. Our works are to believe in Jesus.
In Jesus we're:
Righteous, Rom 4:5,
Holy, Rom 11:16,
Sanctified, Heb 10:10,
Perfected, Heb 10:14,
Cannot sin, 1 John 3:9
But if we're doubting God's promise because we expect to see physical proof in our behavior/lifestyle, then that is not of faith.
Our old man is dead because of sin, Rom 8:10. Henceforth we regard nobody according to the flesh, as we're a new creation, 2 Cor 5:16 We should see ourselves as God sees us. We're totally cleansed/purged of sin by Christ's perfect sacrifice. We (the new creation) have ceased from sin, 1 Pet 4:1 As for our imperfect physical body, it's dead (by faith) because of sin.
Believe in Jesus