For the sake of satisfying curiosity, I've scrolled through my submitted images that didn't make it through and grouped them below by topic.
Memes promoting my religious views:
imgflip.com/i/gn3kv Against evolution
imgflip.com/i/jbm1r Pro Calvin's Institutes
imgflip.com/i/k43g4 Pro TULIP
imgflip.com/i/l4add Matthew 5:28 (against lust)
imgflip.com/i/lbr1h The Bible is against Free Will
imgflip.com/i/lwzei Against Liberal Protestants
imgflip.com/i/nfqml Against Richard Dawkins
imgflip.com/i/o2pfa Gay Marriage controversy
imgflip.com/i/o8czn Martin Luther - Monergism
Memes that were otherwise controversial:
imgflip.com/i/gc09v Charlie Hebdo incident
Unknown reasons:
imgflip.com/i/fhz3v Wonka meme "apology"
imgflip.com/i/fryh5 Bad Luck Brian dumped by Overly Attached Girlfriend
imgflip.com/i/fryiw Overly Attached Girlfriend meme
imgflip.com/i/id2yb That'd be Great pun
imgflip.com/i/juz2h If you watch Godzilla backwards (repost)
imgflip.com/i/k7fec Terminator won grand prize at Avoriaz film festival
imgflip.com/i/kz17m Dat Dodo Dodo
imgflip.com/i/l7oe2 Ain't Nobody Got Time to Make Captions
imgflip.com/i/l7xrl Snoopy Writes to Facebook
imgflip.com/i/lgccu BB-8 Droid from Star Wars Episode 7
imgflip.com/i/lpoql Meryl Streep from Into the Woods
imgflip.com/i/nz1i9 Ariana Grande wants a Donut
imgflip.com/i/o0x16 Grumpy Cat says No
imgflip.com/i/o2q7g Making fun of repost outrage
imgflip.com/i/o8dzx Fake vacation pictures (repost)
imgflip.com/i/om4b3 Sharknado 3 meme
imgflip.com/i/onxfa Success Kid trollface
Hope that helps!