This doesn't support the contention of the OP that a person can hear, then walk off as a believer and live how they want to live which is what you are arguing.
Ann and myself have both contended that the life will bear fruit or evidence of regeneration. You are using Scripture to combat such a Biblical notion. In addition, the context of 1 Corinthians 3 isn't supporting your premise by any means.
I think it does. These Corinthians apparently were still visiting the Pagan temple. (2 Corinthians 5:14ff) and commiting other sins which were vile even to the unbelievers.
12 Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble;
13 Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is.
14 If any man's work abide which he hath built thereupon, he shall receive a reward.
15 If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire.
16 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?
17 If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are.
18 Let no man deceive himself. If any man among you seemeth to be wise in this world, let him become a fool, that he may be wise.
Christians are capable of great wickedness. Sooner or later every Christian worker finds this sad fact to be true.
Revelation 2
20 Notwithstanding I have a few things against thee, because thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols.
21 And I gave her space to repent of her fornication; and she repented not.
22 Behold, I will cast her into a bed, and them that commit adultery with her into great tribulation, except they repent of their deeds.
23 And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works.
HankD