Jesus came to save the world from sin, not to condemn, but there is a condemnation that will separate us from God.
John 3:16 For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. 17 For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
18 “He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. 19
And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For everyone practicing evil hates the light and does not come to the light, lest his deeds should be exposed. 21 But he who does the truth comes to the light, that his deeds may be clearly seen, that they have been done in God.”
John makes the clear distinction that believing in Jesus is related to our obedience to Him. Those who choose to do evil (sin) does not come to the light because their deeds are evil, but we are called to come to the truth (light) so our deeds can be exposed. This is what the Ten Commandments does- it shows us our sin just like a mirror. When we bury our sins (stay in darkness) we don't confess or forsake them and therefore God can't give us His mercy and grace and give us the power to help overcome.
Proverbs 28:13 Those who seek God want to come to the Truth so Jesus can help us overcome our sins. Our salvation is from sin
Mat 1:21 not in sin.
Jesus in His own Words tells us that it's more than just believing...
Matthew 7:21 “Not everyone who says to Me, ‘Lord, Lord [believer],’ shall enter the kingdom of heaven,
but he who does the will of My Father in heaven. 22 Many will say to Me in that day, ‘Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?’ 23
And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness!’
Believing is a great first step but as our love for Jesus grows, we should want to obey Him through faith and love.
Rom 3:31 1 John 5:3 John 14:15 Exo 20:6