Please study the Bible. I’m on my phone or I would give you the verses, which I’m sure you know, which include the commandment to confess with your mouth, to repent of your sins, even to be baptized for the remission of sins.
Unfortunately, far too many people believe your false doctrine. Sure they believe in Jesus Christ, sure they have faith in Jesus Christ, but they have never repented of their sins, they have never confessed the name of Christ. they have never been baptized for the remission of sins and they have never become a disciple of Christ.
And they are lost for all eternity. All because of a false doctrine of faith only.
The doctrine of "faith alone" is NOT false! Repentance is to change your mind (metanoein - to change one's mind or purpose). You turn away/change your mind from relying upon dead works to save you to Jesus Christ who is the propitiation for all our sins. The gift of God is eternal life through Jesus Christ our Lord (Romans 6:23). Baptism is the New Birth - we are baptized in the Holy Spirit when we come to Christ in faith, when we believe in Him as our Savior. Water baptism can come later when we decide to make a public testimony of our faith in following Jesus Christ - water baptism is a "work" and we are not saved by our works LEST ANY MAN SHOULD BOAST (see Ephesians 2:8,9). When you start insisting people MUST do this or that, must NOT do this or that, you are adding works to salvation and you are nullifying grace. Grace means UNMERITED, UNEARNED, UNDESERVED. We are saved BY grace THROUGH faith.
No one is suggesting we should tell people to just say they believe in Jesus and they can go out and live however they want. True, genuine, heart-felt faith in Christ results in a new birth, we are born again from above and have a new spirit nature that is indwelt by the Holy Spirit of promise. He has sealed us until the day of redemption. And because we are now children of God, He disciplines and chastises us as He is conforming us into the image of Christ. He is working within us to sanctify and purify us so that we bring Him glory and draw others to faith in Christ. If we sin, we confess and He forgives us and cleanses us from all unrighteousness. It is a process that He is working within each one of us in our own way. For it is God who works in you to will and to act on behalf of His good pleasure. (Philippians 2:13). Salvation IS a free gift of God's grace and we receive that gift through faith/believing in God's promise.
Your questions arsie because you do not know what being Born Again is, to the soul and spirit. The soul, which is the behavior mechanism interfacing with the body, is not born again when one is born again in the instant they believe on Whom God has sent for their salvation. It is the spirit that instant which is born again, by the power of The Word of God which separates the sinful soul from the born again spirit. And you might ask “So what then?” well, 1 John 3, especially verse 9 is your answer; God abides in the born again spirit. The behavior mechanism can be then transformed by the renewing of the mind of the sinful soul, as the newborn yields to the GENTLE PRESENCE of the abiding GOD LIFE in the newborn spirit.