When speaking of Islamic conquests of Christian lands prior to the Crusades - actually beginning 400 YEARS BEFORE the Crusades - we hear Muslim apologists give this inane "moral equivalence": Well, the Christians were just as bad with their Crusades. No, they weren't. Christians exercised excess patience waiting as long as they did in reclaiming lands that were Christian for several hundred years before Islam even existed.
I've heard Christians in Bible studies compare various religions. In discussing competing world religions and worldviews, I've listened to all forms of distorted moral equivalencies. Recently, in one such discussion, someone brought up the the "horrible" "satanic" religion of Islam. They continued by asserting that Jehovah's Witness, Mormonism, and Christian Science are just as bad. I had to jump in and point out their severely out of whack moral equivalence in their analogies. Traditional Christianity and Mormonism, for example, are two forms of Christianity; part of the same family - as close as the sea is to the shore. Islam, on the other hand, is miles from Christianity, as far as to the moon in comparison.
These careless attempts at moral equivalence with Christianity are done out of ignorance, for the most part. Although those who don't share the Christian faith will attempt these deceptive equivalencies out of malice or their pro-Islamic agenda.
Many in our Churches, including Pastors and other leaders, also share this ignorance, and will put forth similar erroneous moral equivalencies in their feeble attempts to make their point, whatever it may be.
Popes and Pastors will claim Islam and Christianity share the same God. No, my dear ignorant ones, they are not anywhere near the same God. They are moral opposites, not equivalents.
When reminding fellow believers that homosexuality, especially its continuing practice, is unBiblical and a vile sin, some will defend homosexuality and say it is not worse than any other sin, like adultery or cheating. They ignore the fact that the great majority of homosexuals insist on persisting in their sin - even within the church. Persistent adultery or cheating will (or should) get them thrown out after the second Committee meeting.
Oh how much fun it is to disrupt Church order will our excuses of "moral equivalency."