Syncretism is the attempt to reconcile different schools of thought, most notably religions. Syncretism takes place when foreign beliefs are introduced into an indigenous belief system, i.e. missionaries.
In the modern world, religions such as Unitarianism could be considered syncretic in that it is a blending of differing belief systems that are constantly evolving.
Syncretism should not be confused with the adoption of formal elements of other religions into Christianity for missionary reasons.[note 1] It is not just simultaneous practice of two unrelated religions motivated either by external pressure or inner anxiety but it rather equates heterogeneous religious elements and thereby changes their original meaning without admitting such change.
The Word ‘syncretism’ does not expicitly occur in the Bible. Still, the reality of it was an ever-present phenomenon throuout the biblical history. According to Plutarch, the semantic origin of the term relates to the island of Crete. The rivaling Greek tribes there were usually involved in minor warfare against each other. However, as soon as the island was attacked by a common enemy from outside, they suddenly were able to agree on formation of military alliance. Since then the word ‘syncretism’ carries a note of an opportunistic fraternization without a deeper conviction. 
Forms of Syncretism
Hendrick Kraemer, the late missiologist, distinguished between two forms of syncretism that could be found in biblical times as well:
- spontaneous primitive syncretism as a popular religious tendency and
- conscious, philosophical construction of syncretism attempted typically by religious thinkers or by political rulers.
- cf. Acts 17:23
- Peter Beyerhaus (1975). "6:Possesio and Syncretism in Biblical Perspective", Christopaganism or Indigenous Christianity?. South Pasadena, California: William-Carey Library, 126-127. ISBN 0-87808-423-1.