2) Islam (Followers: 1,600 Million)
Islam is a monotheistic religion articulated by the Quran. People who follow Islam are known as Muslims. They believe Quran to be the verbatim word of God. They consider Muhammad as the last prophet of God. They believe that God is one and incomparable.
1) Christianity (Followers: 2,200 Million)
Christianity is a monotheistic religion based on the life and teachings of Jesus Christ as presented in the New Testament. It is the largest religion in the world. Followers of Christianity are known as Christians, who believe that Jesus has a unique significance in the world. Christianity played an important role in Western civilization.
These great religions have being guiding millions worldwide for centuries.