Mankind is incapable of living a sin free life. God’s plan of salvation requires everyone to accept that fact and be saved through the blood of Jesus. In order to prove humans can’t live sinlessly, God let them try. Except for a few faithfull, from Adam until the Mosaic law, mankind lived according to their own desires. This first, vast group of humans amply demonstrated mankind’s inability to live lives free of sin.

That group of humanity might argue, if they had laws to follow, they would have been able to live sinlessly. To prove humans incapable of living free of sin, even with rules, God gave them ten to follow, along with a helpful religious framework. Even with the Jewish religion showing how to follow God, no one was able to live a perfect life. 

Finally Jesus came to earth to show that it was possible for humans to live a life free of sin. Further demonstrating Jesus is the only one able to live a perfect life, those who follow Jesus as disciples, receive the same holy spirit power Jesus had. Even with the spirit of God living in us, we are still unable to live sinlessly. Proving to all humanity, from every time period, that accepting the covering blood of Jesus is the only way to have their sins blotted out. What must people do in order to be saved? Does that apply to everyone who has ever lived? Are there any exceptions to following Jesus? Can babies who die be sinless if all have sinned? 

1 John 1:8-10 English Standard Version
8 If we say we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. 10 If we say we have not sinned, we make him a liar, and his word is not in us.

Acts 4:12 New Century Version
12 Jesus is the only One who can save people. No one else in the world is able to save us.”

1 Corinthians 1:28-30 Easy-to-Read Version
28 And God chose what the world thinks is not important—what the world hates and thinks is nothing. He chose these to destroy what the world thinks is important. 29 God did this so that no one can stand before him and boast about anything. 30 It is God who has made you part of Christ Jesus. And Christ has become for us wisdom from God. He is the reason we are right with God and pure enough to be in his presence. Christ is the one who set us free from sin.

Romans 3:23 Easy-to-Read Version
23 All have sinned and are not good enough to share God’s divine greatness.