When "debating" with Christians, you can expect the following forms of sophistry to be used on their behalf. Which's not suprising. Sophistry and Abrahamic religions, much like Jews and sophistry, go hand in hand. To quote Pope Pius XI from 1937 (note: this is *prior* to Vatican II): "Spiritually, we are all Semites".
(1) ad hominem attacks (which, interestingly enough, are *never* applied consistently to fellow Christians– only pagans, heretics, etc). Very childish.
(2) high IQ theological acrobatics (see: RCC / EO dogma. Argument by extension. The Bible says X, theologians will then say "based on X, we can assume Y", another theologeon will extend this again: "based on Y we can say Z", etc. Like how Christianity went from "blessed are the poor" to the assertion, by certain Calvainists, that one's personal wealth is correlative to their likelihood of being saved)
(3) deliberate vagueness in their assertions or arguements.
(4) accuse the opponent of ignorance but not backup with any evidence (if there is evidence, see #2).
(5) appeals to authority ("the church/bible is always right"– Muslims, Jews, Mormons and literally *all* Abrahamic religions make this claim. It's based entire on one's upbringing. No reasonable god would damn someone for adhering to what they were raised to believe, unless their god was unreasonable– which, many nominalists did/do actually assert, and which's *not* logically inconsistent).
(6) flat-out ignore accusations or counter-arguments (i.e., talking over the opposing party. Same as basic-bitch conservatards and libtards "debate" with one-another).
(7) pick out the weakest part of opponents argument and attack only those to draw attention away from the mainstay
(8) find any way possible to misconstrue the opponent's argument and attack that. I.e., attack the "accidental" qualities of the arguemend, rather than it's essential qualities.
(9) overly-simplistic analysis. For example: "that the left opposes the True Church(tm) is proof that it's correct". While at the same time, ignoring that the revolution eats it's own and that the left also opposes other forms of leftism. E.g., the USSR suppressed the Industrial Workers Of The World and various other leftist movements. This does not necessarily lend validity to the IWW's political platform.
Actually, this's generous. I've likely missed a few, but this post's already far too long as it is. You could go onto the "list of fallacies" Wikipedia article and all or almost all of them would likely apply. These're just the ones I've noted, off the top of my head, as being most occorant.