Belief in Jesus is a term generally synonymous with Christianity, indicating (generally speaking) a view that Jesus was or is a being who was anointed by God as the Messiah prophesied in Judaism, and that his Gospel ("good news") is a profound and loving message from God to all human beings —most dominantly conveying a message of hope for the transcendence of the soul, divine justice, and an eternal life for those who believe.
Beyond this view however, Christian theology is a vast, varied, differentiated, and mythical landscape. Many concepts with "Christianity" appear to contradict one another, or else they appear to be incompatible with other "Christian" views. And the concept that "belief in Jesus" can be discussed separately from "Christianity," raises some profound questions:
In general, most "Christians" (~90%) are associated with a religious institution (a "Church," or denomination) that adheres to the Nicene Creed, which affirms the general belief that Jesus was the Messiah on Earth. Within this creed are several other doctrines: