That's not in my Bible
Many Christians are not familiar with large sections of the Bible; and, as such, have not have noticed some of its odder or more abhorrent passages, such as the injunction against wearing clothes of wool and linen (Deuteronomy 22:11 ) or Jephthah's human sacrifice (Judges 11:30-40 ). Such people may express disbelief that such things are in the Bible.
The best way to counter this argument is to show the person the relevant passage. There are several web sites and books that list questionable passages in the Bible.
There are also searchable Bible applications for smartphones, PDAs, and other mobile devices. It can be useful to have one as a reference.
The most famous incident of human sacrifice is the Akedah,(Genesis 22:1-24 ) the Binding of Isaac. It is worth noting that, though Abraham is commanded by God to sacrifice Isaac at the mountaintop, God intervenes at the last moment. There has been a great deal of work on this in Jewish apologetics and Christian apologetics. There is a corresponding story in Islam, which credits the son as Ismail instead of Isaac.
Jephthah ritually sacrifices his daughter to God (Judges 11:29-40 ) after vowing to sacrifice the first thing that greets him when he returns from his military victory over the Ammonites.
After the Israelites violate God's commandments, God commands Joshua to instruct the people in ritual repentance, which includes the destruction of those who violated the covenant by fire. (Joshua 7:15 ) It is ambiguous as to whether this is ritual sacrifice performed by the tribe or whether it is performed directly by God.
According to Deuteronomy, the punishment for raping a woman who is not engaged is restitution of fifty-pieces of silver to the woman's father, and the man is required to marry the woman he has raped. (Deuteronomy 22:28 ) Divorce is prohibited, (Deuteronomy 22:29 ) and the woman has no right to divorce. If a man rapes a woman who is engaged, both the man and the woman are to be stoned to death; the woman because she did not cry out for help. (Deuteronomy 22:23-24 )
Throughout the Bible, rape is encouraged as a military tactic, and sanctions the raping of virgin women as prizes of war.
At Jabesh Gilead, (Judges 21:10-12 ) Israelites kill all of the men and non-virgin women. They take four-hundred virgin women to their camp. While the passage is vague, it does strongly imply that those women were raped.