Is there a sin of all sins? Jesus spoke of one in the book of John. “Then Jesus said to them again, “I am going away, and you will seek Me, and will die in your sin. Where I go you cannot come.” John 8:21. Notice “sin” is singular, one sin.

The sin that Jesus was speaking of was the sin of rejection; the Religious leaders rejected Jesus as the Messiah, The Son of God. When we do not believe in Jesus, we are dead.

“But because of his great love for us, God, who is rich in mercy,  made us alive with Christ even when we were dead in transgressions—it is by grace you have been saved.” Ephesians 2:4-5