Why to follow Islam

God has revealed different religions in different eras to guide mankind to heaven. The question to ask is whether one can follow the former religions or shall they convert to the new religion. According to Muslims, Islam is the last divine religion which is comprehensive and designed for all times and after its revelation, it is a must for everyone to follow it and following other religions is not true. There are three reasons why it is not true: first, change (alteration) in divine books; second, proofs in other former religions; and third, last of the prophets and comprehensiveness of Islam. The first reason needs to be assessed in another research; however, the second and third reasons support necessity of following Islam.