Many times in the Bible God kills people, sometimes large numbers of people. Bible critics say this shows that God was cruel, and that he was immoral, because he didn't follow his own commandment not to murder people.
Once again the Bible critics are confused. First, with regard to God not following his own commandment, we have to point out that just because it's wrong for a human to kill somebody doesn't mean that it's wrong for God to do it. Consider the following illustration:
Suppose someone kills a friend of mine. Do I have a right to hunt that person down and than kill him in revenge? No. That would be vigilantism. I don't have the authority to carry out the punishment for murder. But the government does. The government is the entity that has the authority to arrest a murderer and punish him (by execution or life imprisonment).
Similarly God has absolute authority to decide when people live or die. We humans don't have that absolute authority. Just as government has the authority to kill when I don't, so God has the authority to kill when we humans are told "Thou shalt not kill."
Calling God a "murderer" for killing an evil person would be like calling the government a murderer for executing a criminal after conviction in a fair trial.
Everywhere in the Bible when God kills someone, or commands someone to be killed, it is done as a punishment for sin. Sometimes he punishes individuals for their sin. But sometimes he punishes whole groups of people for their sin, as with the destruction of Sodom and Gomorrah, or of the Canaanites (Deut. 20:16-18), or of the whole earth in the Flood.
But this gives rise to the next question: When God sends punishment on a group of people, isn't he punishing the innocent along with the guilty? For example, when God sent the flood, he did it because
...the earth was corrupt in God's sight, and the earth was filled with violence. And God saw the earth, and behold, it was corrupt; for all flesh had corrupted their way upon the earth. (Gen. 6:11-12)But in doing so, God would have killed not just the sinful adults, but infants as well, who could not be regarded as guilty of sin. So is God being unjust here in killing the innocent along with the guilty? The Bible critics say he is.
However, if you're going to criticize actions imputed to God in the Bible, you have to criticize the whole action, and not just part of it. According to the Christian understanding of the Bible, what happens to innocent children when they die? We all know the answer to that. They go to heaven.
So if the Bible is true, and God decrees that the earthly life of some children will end and they will go to heaven, is God being unjust or cruel? Well, rewarding someone with an eternity in heaven is certainly not unjust. Life on earth contains much suffering for all of us, but for those who spend eternity in heaven, the pains and sorrows of this life will be wiped away and forgotten, exchanged for eternal joy with God.
You can't beat that. But, returning to this earthly life, we still have the question: Even if God did take the innocent children into heaven, why would he kill them for the sins of their parents?
I think it's due to the principle of group responsibility that we see in the Bible. Individuals share in the guilt or righteousness of the group they are part of. For example, humans (even infants) share in the sin of Adam, because we're all part of the human race. Nations can have corporate guilt. Families too can suffer its consequences.
Why did God set up this principle of corporate righteousness or guilt? I think it was meant to be a blessing, in order that the consequences of righteousness would be passed on to one's family and one's descendents. But sin makes it a curse. What was meant for good became evil.
However, God provided a way out. Group responsibility is counterbalanced by the fact that each individual can repent and be forgiven. We did not have a choice in being born with a sinful nature; instead we have the equally valuable choice of accepting God's forgiveness for our sin and becoming righteous in Jesus Christ. Adam started out good, but made the choice to become evil. We start out evil, but we can make the choice to become good, through Christ. Each one of us has the same opportunity Adam had of choosing between good and evil.
However, group responsibility still holds in this life. We all have a choice about accepting or rejecting salvation, but in this life we still all of us suffer consequences of sin, both our sins and others' sins. Many children suffer from their parents' actions. We can observe that all around us, from crack babies to child abuse.
Group responsibility is balanced by individual freedom of choice. God is fair. The sufferings of this life are wiped away by the joys of heaven. God showers joy and blessings on his children. So if the Bible is true, then God is not unjust, immoral, or cruel.
God punishes the wicked and rewards the righteous and the innocent. Now if the Bible critics can prove that the Bible is not true, e.g. that there is no heaven where our sufferings are rewarded, then they have a case. But they cannot prove that the God who is depicted in the Bible is anything but just and righteous.