Syncretist

noun

1. One who attempts to blend incongruous tenets, or doctrines of different schools or churches, into a system.
2. Specifically— A follower of Calixtus (1586–1656), a Lutheran divine, and professor of theology at Helmstedt, who endeavored to frame a religious system which should unite the different Christian denominations, Protestant and Catholic.
3. One of a school, in the sixteenth century, which attempted to mediate between the Platonic and Aristotelian philosophies. Also used attributively: as, a syncretist religious system.
4. One who attempts to unite principles or parties which are irreconcilably at variance
5. One who attempts syncretism, the fusion of different systems or beliefs.