If Christianity and abortion are compatible, so are
Christianity and infanticide,
Christianity and euthanasia,
Christianity and adultery (of which same sex relations is just a variant),
Christianity and thievery,
Christianity and spousal abuse,
Christianity and child abuse,
Christianity and drunkenness,
Christianity and gluttony,
Christianity ... well, you get the picture by now.
Yes, and the Ten Commandments can also be tossed and these people will have achieved the perfect religion for themselves. At that point, they will all convert to Christianity.