Wherefore doth the wicked contemn God? he hath said in his heart, Thou wilt not require it.
Psalm 10:13
To say that “God will not require it” is KJV language to say: God will not take vengeance | justice.
And surely your blood of your lives will I require; at the hand of every beast will I require it, and at the hand of man; at the hand of every man’s brother will I require the life of man.
Genesis 9:5
The man who sheds blood, God will require the same of him. Eye for eye, tooth for tooth. Blood speaks of life, so in other words, it is life for life.
When God speaks of what he will require of the wicked, he is speaking of: Vengeance! Justice! Judgment!
To me belongeth vengeance, and recompence; their foot shall slide in due time: for the day of their calamity is at hand, and the things that shall come upon them make haste.
Deuteronomy 32:35 KJVS
And God promised many times that he would take vengeance on the wicked: If I whet my glittering sword, and mine hand take hold on judgment; I will render vengeance to mine enemies, and will reward them that hate me. – Deuteronomy 32:41
God is jealous, and the LORD revengeth; the LORD revengeth, and is furious; the LORD will take vengeance on his adversaries, and he reserveth wrath for his enemies. – Nahum 1:2
How does this concern | testify Jesus?
Say to them that are of a fearful heart, Be strong, fear not: behold, your God will come with vengeance, even God with a recompence; he will come and save you. – Isaiah 35:4 S
Our God (Jesus) did come and save us, but what about the vengeance and recompence? Vengence and recompence was part of the salvation package.
How you ask 🤔 ❓
Let the saints be joyful in glory: let them sing aloud upon their beds. [6] Let the high praises of God be in their mouth, and a twoedged sword in their hand; [7] To execute vengeance upon the heathen, and punishments upon the people;
Psalm 149:5-7
Notice, the people of God have the twoedged sword (The Word of God) in their hand and the purpose of it is to execute vengence on the heathen…

How do we (the people of God) do that (execute vengeance)?
We kill the flesh by speaking the word of God. That’s how!
The same way, someone was armed with the sword of the Spirit (the Word of God) swung it and killed the carnal | sinful man in us (when we became believers).
And take the helmet of salvation, and the sword of the Spirit, which is the word of God:
Ephesians 6:17
So God requires of us all, cause we were/are all wicked – to kill the flesh.
In Christ the requirement is met i.e. vengeance is taken, the carnal sinful man is slain, and with his (Jesus’s) death via the word of God, we can live by the same word.
But for those who reject Christ: vengeance, recompence is yet required.
Selah!