Acts 3:19 DOES NOT say "turn away from sinful behaviors" in order to be saved. Repent-of-sinnists, corrupt modern versions, works trusters, and hereticks, often twist biblical repentance and Acts 3:19 into unbiblical, various "repent of sins" or workist heresies when those direct word phrase are not mentioned here: Acts 3:19 says repent (change of mind) and be converted, that your sins may be blotted out. Before someone converts, they understand with the gospel with their heart and then turn from unbelief to belief. When they understand, they have the opportunity to & can repent/change their mind from unbelief to belief.

Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord; (Acts 3:19). For this people's heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes, and hear with their ears, and should understand with their heart, and should be converted, and I should heal them. (Matthew 13:15). Jesus defines converted to mean to come to him by faith in him alone: And said, Verily I say unto you, Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven. But when Jesus saw it, he was much displeased, and said unto them, Suffer the little children to come unto me, and forbid them not: for of such is the kingdom of God. Verily, verily, I say unto you, He that believeth on me hath everlasting life. Thus: I believed, therefore have I spoken: I was greatly afflicted: (Psalms 116:10)