A Muslim believes in all the prophets of Allah and the prophets gave the concept of loving humanity. The prophets also asked the human beings to serve others in the best possible way. The teachings of Mohammad (saw) are not different from the other prophets. His Ahadith are full of commands relating to human rights.
Prophets also asked us to believe in one Allah, follow His way and not to make partners with Him. This concept of Tauheed takes us out of the slavery of other human beings. The prophets told us about the Day of Judgment which means that if we truly believe in the Day of Judgment, we will never do any wrong with the other creation of Allah because we are answerable to Allah.
The worships were taught by the prophets. Salat, Saum and Zakat are useful for our daily life in many different ways. For these reasons, belief in prophets is an important concept of human life.