I mean...it's so clear that other religions consider Christianity idolatry, just because we believe that Mary, a woman from Nazareth, is the Mother of God.
That is, she delivered Jesus, Son of God, and part of the Holy Trinity.
But I believe that it's because we believe there is not a clear line between humane and divine, because they permeate each other in a beautiful communication and it is not possible to say where one starts and the other ends.
Jesus is God. As Monsignor Poma, a Catholic priest once said: Jesus went to the Cross to mean that the sacred is the Humane.
Keep in mind, that idolatry is considered a sin in Christianity too, but we consider idolatry the worship of other things, other than God.
There are people that love money more than God and so they worship money as a idol to preserve, forgetting we are all mortals and that money will remain, we will die.
That's idolatry and that's a deadly sin.
Or some other Christians worship power. That's idolatry.
But worshipping Jesus as Son of God is not idolatry. He is our Salvation, our purpose, our meaning. That means that mankind can evolve into a divine form, and Jesus has taught us why.
So many people start crying hearing young Jesus.