The Gospel is a very simple message. It is so simple that many people cannot believe it or understand it.
Paul said to the Corinthians, "I fear, lest by any means , as the serpent beguild Eve through his subtility, so your minds should be corrupted from the simplicity that is in Christ" 2 Corinthians 11:3.
The Gospel is so simple that even little children can hear it, believe it and be saved. Here is the simple message of the Gospel that I taught children when I was the pastor of the childrens church.
Jesus has come into the world as our substitute and representative, to do for us that which we cannot do for ourselves because we are sinners. Jesus has fulfilled God's Holy Law for us. Jesus has atoned for our sins. All that Jesus did was for us, and to make us pleasing to God. Jesus makes us right with God.
There it is in less than 60 words. The simple Gospel message that even a small child can understand. The Calvinist "Cannons of Dort" have composed 20 pages on what you have to do to become or believe in Calvinism.
When it comes to complicated religions Catholicism takes first place. Before you can become a Catholic you have to go to Catechism where they give you a manual about how you can become a Catholic. The "Council of Trent" has composed over 30 statement on what a Catholic must do and believe. At the end of each statement it says that if you don't do or believe those things then, "Let him be anathema" which means kicked out of the Catholic church. This is why you don't ask any questions or oppose any thing in the Catholic church.
Religion is complicated. I have noticed that some Forum members compose long post about their religion and what they believe. I seldom read them because it is pure religion. I suspect that they have been deceived by the "Simplicity that is in Christ".