In the beginning, man disobeyed God and followed the leading of the devil.
"...For all have sinned and fall short of the glory of God..." (Romans 3:23)
This was an extremely serious problem because the wages of sin is death. (Romans 6:23)
God had an answer...
God had prepared for this and was willing to give his Son's life to pay for our sins. (Romans 5:8)
Jesus tells us...
That we must be born again to inherit the kingdom of God. (John 3:3)
He came to give us real life, the best life possible here on earth and then in heaven with Him. (John 10:10)