(A review to the book Drunk With Blood: God's killings in the Bible)
You judge from your limited observation. God's killings are actually acts of grace. If He had not killed all living creatures except Noah, the earth would have been hell, because of the hybrid- people - half fallen angel- half human being that satan had poluted and filled the earth with. KILLING THEM saved God's plan and the uncontaminated human race by one man: Noah. For only Noah was perfect in his generations - UNCONTAMINATED BY SATAN'S SEED!
And as Jesus foretold that the last days were going to be as the days of Noah - meaning: the human race would again be polluted - they are experimenting now with animal DNA in human bodies etc.
God had a choice: Either destroy the whole earth and everone, because satan had corrupted all living matter, including Noah and the animals God led to the Ark. Simply to start all over. He had done that once already: Because the earth was not made void when God created the heaven and the earth. NO IT BECAME VOID, when satan and 1/3 of the angels who followed the archangel Lucifer in his rebellion battled God's angels. The creation account from Genesis 1: 2c is actually a SECOND CREATION!
God - in His incredible grace did not want to kill the only perfect seed left (Gen. 6:9) - so He spared the earth and a sample of all animals for the sake of one man!
THIS IS GRACE! But you look at all the hybrid humans God killed. This killing does not make God cruel at all. But rather the very opposite of a cruel genocidal murdered. The bad guy was satan who contaminated all human seed.
The reason for satan doing this was the curse over him, the prophecy God had given Eve after sinning: "And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel." (Genesis 3:15)
Satan figured that the only way he could prevent this - his total destruction and defeat - from ever coming true was to prevent the developping of that seed! This is what he did by contaminated the human seed with his seed. God could never fulfill His plan of salvation, which this verse speaks of and is God's promise right after the all of men. That seed God promised in Genesis 3:15 is Jesus Christ, the only begotten Son of God!
So, you see God's grace in the absolute necessaity of killing all flesh with the exception of Noah!
As for the other killings by God, similar explanations can be given. God kills to redeem! God ALWAYS LOOKS AT THE BIGGER PICTURE, THE GREATER PURPOSE.
Satan murders out of hatred, as we were created in the image of God. Satan hates God and therefore satan hates us. He knows God loves us, so that murdering people is the way to hurt God.
I stand in awe of God, when I consider this! His infinite wisdom!
Knowing this, I consider all these accusations of people of God for His killings such folly. They have no idea. But they have such a big mouth...these created beings against their Maker!
In addition: God's grace is also visible in the fact that sin resulted in death! Sin brought death into the earth!
Death is an act of grace by God for if God had allowed men to live for ever, this earth would have been hell! It would have meant sin would have been perpetual.
Thank God all men die since sin came into the world by Adam and Eve.
God's plan from the beginning was to create men to be with Him for ever! But since men chose to disobey Him, and sin - go their own way, do their own thing - God had to make the penalty of sin: DEATH! For He can not allow sin to exist for ever!
This proves God's unlimited wisdom, and also His LOVE!
In the end death will be thrown into the Lake that Burns with Fire and Brimstone! (Rev. 21:8)
On top of this: He provided the sacrifice in His very own only begotten Son of God to die for us, paying the penalty for our sin, so by His resurrection from the dead, He overcame death and opened the way for us to be reconciled with God, to be forgiven and to be free from the penalty of sin, the second death (Rev. 21:8) and live with Him for ever, as He had intended from the beginning! All we have to do now I call upon Him, repent of our sins, our unbelief, our rejection of Him, our going our own way, and ask His forgiveness and that He makes us His child, lets us be born -again, and destroys the plan of satan with our lives and releases His plan for our lives, and teaches us to walk with Him, commune with Him - for He is not dead, but He is alive and wants to have fellowship with us. For ever! John 1:12,13; John 3. John 14:6. Acts 2:38; Acts 4:12. 2 Corinthians 5: 17; Galations 6:15; etc.