goldmoor,
God Himself (character, morality, etc.) never changes, but that does not mean that He does not change His mode of operation. God created and then stopped and He will create again in the future. The Holy Spirit did not permanently indwell believers back then, now He does. There was no Spirit powered "salt and light" in the world, back then. Although, Israel was to be God's witness.
Romans 12:14 Bless those who persecute you; bless and curse not.
15 Rejoice with those who rejoice, and weep with those who weep.
16 Be of the same mind toward one another; do not be haughty in mind, but associate with the lowly. Do not be wise in your own estimation.
17 Never pay back evil for evil to anyone. Respect what is right in the sight of all men.
18 If possible, so far as it depends on you, be at peace with all men.
19 Never take your own revenge, beloved, but leave room for the wrath of God, for it is written, "VENGEANCE IS MINE, I WILL REPAY," says the Lord.
20 "BUT IF YOUR ENEMY IS HUNGRY, FEED HIM, AND IF HE IS THIRSTY, GIVE HIM A DRINK; FOR IN SO DOING YOU WILL HEAP BURNING
COALS UPON HIS HEAD. "
21 Do not be overcome by evil, but overcome evil with good.
Romans 13:1 Let every person be in subjection to the governing authorities. For there is no authority except from God, and those which exist are
established by God.
2 Therefore he who resists authority has opposed the ordinance of God; and they who have opposed will receive condemnation upon themselves.
3 For rulers are not a cause of fear for good behavior, but for evil. Do you want to have no fear of authority? Do what is good, and you will have praise
from the same;
4 for it is a minister of God to you for good. But if you do what is evil, be afraid; for it does not bear the sword for nothing; for it is a minister of God, an
avenger who brings wrath upon the one who practices evil.
As Paul stated it, individuals are not allowed to take revenge. It is a matter for those in authority to decide.
Even when God gave the LAW He made this clear, Exodus 21:22, 22:8-9; Numbers 35:9-31: Deuteronomy 19:1-21.