Guess you never read of the countless times God told Israel to put such and such person and or nation to death.
God could have done it Himself.
"And he spake a parable unto them to this end, that men ought always to pray, and not to faint; Saying, There was in a city a judge, which feared not God, neither regarded man: And there was a widow in that city; and she came unto him, saying, Avenge me of mine adversary. And he would not for a while: but afterward he said within himself, Though I fear not God, nor regard man; Yet because this widow troubleth me, I will avenge her, lest by her continual coming she weary me. And the Lord said, Hear what the unjust judge saith. And shall not God avenge his own elect, which cry day and night unto him, though he bear long with them? I tell you that he will avenge them speedily. Nevertheless when the Son of man cometh, shall he find faith on the earth?" (Luke 18:1-8)
"When the Son of man comes" or when Jesus Christ returns, He will avenge His elect who have been crying out to Him day and night IN PRAYER speedily. Notice His question, though:
"When the Son of man cometh, shall He find faith on the earth?"
What type of "faith" was Jesus referring to contextually? To me, it seems as if He was referring specifically to the type of "faith" which DOESN'T AVENGE ITSELF, but which patiently and PRAYERFULLY waits upon the Lord for "Vengeance belongs unto the Lord" and not unto any of us. Do I believe that governments have been given the power or authority to execute God's wrath upon the wicked? Yes, as a matter of fact, I do. This does not mean, however, that I have to be a participant in the same. We'll all give individual accounts for our own lives and I'm personally determined to expend my efforts in sharing the gospel with people as opposed to seeking to have them executed. I would never consent to the death sentence as a juror...not even if one of my own loved ones had been murdered by the person on trial. I know that that's easy to say when it's not presently a reality, but I believe that I would remain faithful to my present convictions no matter what. There are some lines from the movie "Ben-Hur" that I'm always reminded of when these types of conversations arise. You know (if you've seen the movie), the time when Esther says to Judah Ben-Hur:
"I know there is a law in life that blood begets more blood as dog begets dog. Death generates death. The vulture breeds the vulture. But the voice I heard on the hill today said, 'Love your enemy. Do good to those who spitefully use you.'"
I guess that to some "Love your enemy" means executing him. Go figure.