Some argue that it was immoral for God to command the killing of entire nations, including women and children, in the Bible. However, there are several responses to this argument that answer this alleged problem with the Bible.
Moses said to them, “Have you let all the women live? 16 Behold, these, on Balaam’s advice, caused the people of Israel to act treacherously against the Lord in the incident of Peor, and so the plague came among the congregation of the Lord. 17 Now therefore, kill every male among the little ones, and kill every woman who has known man by lying with him. 18 But all the young girls who have not known man by lying with him keep alive for yourselves.
Numbers 31:15-18
33 And the Lord our God gave him over to us, and we defeated him and his sons and all his people. 34 And we captured all his cities at that time and devoted to destruction every city, men, women, and children. We left no survivors.
Deuteronomy 2:33-34
So the congregation sent 12,000 of their bravest men there and commanded them, “Go and strike the inhabitants of Jabesh-gilead with the edge of the sword; also the women and the little ones.
Judges 21:10
2 Thus says the Lord of hosts, ‘I have noted what Amalek did to Israel in opposing them on the way when they came up out of Egypt. 3 Now go and strike Amalek and devote to destruction[a] all that they have. Do not spare them, but kill both man and woman, child and infant, ox and sheep, camel and donkey.’”
1 Samuel 15:2-3
The Israelite nation had a unique purpose in history. God’s plan was to use the nation of Israel to eventually bring forth Jesus, the messiah and savior. God’s purpose and plan involved the nation of Israelite obtaining and living in the “promised land,” which sometimes involved warfare with other nations, both for the purpose of obtaining the promised land and to maintain their purity as God’s holy people. Because of this, it is natural to see an association between God’s commands and the complexities of war. To prevent other nations from corrupting the holiness of the Israelites, God sometimes commanded the Israelites to completely eliminate particular nations (although in spite of this, the Israelites continually disobeyed God and corrupted themselves). God’s commands may be judged as unpopular by many, but the reality is that people who object to God’s commands cannot demonstrate that God’s commands were “wrong.” For more about this, see the section, “What Moral Standard Are You Using to Judge the Bible?” below.
God has the right to punish sin. The Bible teaches that every single human has sinned and that the punishment for sin is death ( Romans 6:23). This means that God would be just to kill any human at any time because of that person’s personal guilt and sin. However, God does not do this because of his patience and mercy. When God ”does” end the life of a person because of sin, it is always just and fair for God to do this because the person deserves death because of sin. This means that it was not at all unjust or immoral for God to command the killing of nations, even of women and children, since every individual in that nation was guilty of sin and therefore deserving of death.
To read more answers to alleged and apparent contradictions in the Bible, see “Contradictions” in the Bible Answered.
These books are also excellent resources:
Evidence That Demands a Verdict: Life-Changing Truth for a Skeptical World - Josh and Sean McDowell
Little Pilgrim's Progress (Illustrated Edition) - Helen L. Taylor