syncretism (n.)

"reconciliation of different beliefs," 1610s, from French syncrétisme (17c.) and directly from Modern Latin syncretismus (used by German Protestant theologian David Pareus, 1615), from Greek synkretismos "union of communities," from synkretizein "to combine against a common enemy," from syn- "together" (see syn-) + second element of uncertain origin. One theory connects it with kretismos "lying," from kretizein "to lie like a Cretan;" another connects it with the stem of kerannynai "to mix, blend;" krasis "mixture." Related: Syncretist; syncretistic.