The reason many professing Christians continue to live sinful lives is that they have NOT been born again. They are not saved. It is absolutely necessary to be born again to be saved and enter the Kingdom of God. Salvation is through a Saviour, the person of the Lord Jesus Christ. Because you have sinned.
Mankind is depraved and inclined towards sin.
The penalty of your sin. You are spiritually dead. I. God's Part. Jesus Christ died in your place and for your sins so that you can be forgiven and receive that new life. Choose whom you will serve.