Islam is not a new religion because "submission to the will of God", i.e. Islam, has always been the only acceptable religion in the sight of God. For this reason, Islam is the true "natural religion", and it is the same eternal message revealed through the ages to all of God's prophets and messengers. Muslims believe that all of God's prophets, which include Abraham, Noah, Moses, Jesus and Muhammad, brought the same message of Pure Monotheism. For this reason, the Prophet Muhammad was not the founder of a new religion, as many people mistakenly think, but he was the Final Prophet of Islam.
By revealing His final message to Muhammad, which is an eternal and universal message for all of mankind, God finally fulfilled the covenant that He made with Abraham, who was one of the earliest and greatest prophets. Suffice it to say that the way of Islam is the same as the way of the prophet Abraham, because both the Bible and the Qur'aan portray Abraham as a towering example of someone who submitted himself completely to God and worshipped Him without intermediaries. Once this is realised, it should be clear that Islam has the most continuous and universal message of any religion, because all prophets and messengers were "Muslims", i.e. those who submitted to God's will, and they preached "Islam", i.e. submission to the will of Almighty God.