The author clearly shows the idea of Jesus as part of a Trinity was a Greek Pagan idea adopted by early Christian mission-aries to gain converts among the Greek, and did not become a widely accepted Christian doctrine until after the Council of Nicea in 325 A.D.
This is the way it has always been throughout history: Adam to Nuh, Ibrahrim, Musa, Isa, and Muahmmad (peace be upon them). It will happen to anyone who wants to stand up and proclaim the true message of Islam to the world.