This is the entire significance of faith. The unregenerate man doesn't yet have salvation, he stands condemned, separated, dead to God in the spirit. The unregenerate man doesn't understand the things of the spirit because the unregenerate man is composed of body and soul, without living spirit. However, within the soul of the unregenerate man, is the ability to think, comprehend and exercise faith.
That faith, when applied to the thoughts of God are then made valid by the Holy Spirit in an efficacious grace for salvation. The Holy Spirit then (simultaneous with that faith) creates the new human spirit in the man,...now the man is regenerate.
I suspect if God regenerated man prior to faith, there would be no significance in faith because belief in Him is more significant after regeneration. Faith may be held by the unregenerate. Then it is made by the Holy Spirit efficacious for salvation,...similar to finding the faith of Abraham before he made his sacrifice as being worthy of divine righteousness.
He will by no means ever permit to be lost,
Correct, once saved, the life is eternal,..we have a royal family and blessings in store for us in heaven,...no matter how heinous we behave after salvation.
But any believer who claims they do not sin after salvation is a liar. The following sin of the believer merely removes him from fellowship with perfect righteousness. Sin scars the soul. We return to Him by confessing those sins to Him as we now are our own priests and confess them in faith through the High Priest, Christ Jesus, and they are forgiven. At that point we have returned in fellowship with Him by His work.
Most Christians have fallen out of fellowship in probably any number of innocuous ways, but until they confess and repent their sins, they leave many blessings unclaimed in heaven or they may be given to others here on earth.