When it comes to abortion, homosexuals, religious tolerance, and several other important issues, I’ve noticed far too many Christians tend to fall back on this approach to voicing their opinions.

polemic (po·lem·ic): / puh LEM ik /
noun

(1) a passionate, usually controversial argument; an aggressive refutation of or attack on an idea, doctrine, opinion, principle, etc.
(2) a controversialist, especially an aggressive one; a passionate disputant

adjective

(1) of or pertaining to a passionate argument, refutation, or controversy (also ‘polemical’)

[From Greek polemikos meaning “for or of war, belligerent, hostile,” from polemos meaning “war.”]

Usage: The anti-gay polemic from the Christian mythology is based entirely on selecting a few choice passages from the Bible whilst simultaneously ignoring those before and after them, especially the dozens—and even hundreds—of admonitions and proscriptions targeting the behavior of the faith’s own followers.