The greatest sin

I think the greatest sin is denying the divinity of Christ.I was once talking with a friend of mine who was a good catholic. During our conversation he said "Was not Jesus the son of joseph and mary?"

Even there are catholics who doesn't believe in divinity of Jesus.The basic belief in christanity is the incarnation and resurrection of Christ. If Christ is not God, Christianity is just a house of cards.If there was no resurrection, he was misunderstood rabbi at best or a lunatic who was martyred

The gratest question we face when we talk about the divinity of Christ is has He ever told that He is God? In John 10:30 Jesus says"I and the father are one". In John 8:58 Jesus says “Amen, amen, I say to you, before Abraham came to be, I AM". In old testament God says Iam who Iam.There are 7 Iam sayings of Jesus in the gospel of St.John

I am the bread of life (JN 6:35)

I am the light of the world (JN 8:12)

I am the gate (JN 10:9)

I am the good shepherd (JN 10:11)

I am the resurrection and the life (JN 11:25)

I am the way truth and life (JN 14:6)

I am the true vine (JN 15:1)

After resurrection Jesus is said to have appeared to have appeared to 500 people.Many of them died for this faith.It is impossible for this many people to have the same illusion around the same time period