Could you please provide any supporting verses from the New Testament for this? If you cannot support your statement with a Biblical verse, then it remains an opinion rather than Biblical.
The New Testament does not speak directly about capital punishment - either for or against - yet there is ample evidence in the Old Testament that God does support the practice for various offenses.
However - there are a couple examples from Paul that prove that at least he understood and taught that the faithful were to be subject to Man's laws and that Man had authority to punish offenders even to death.
"Let every soul be subject unto the higher powers. For there is no power but of God: the powers that be are ordained of God.
Whosoever therefore resisteth the power, resisteth the ordinance of God: and they that resist shall receive to themselves damnation.
For rulers are not a terror to good works, but to the evil. Wilt thou then not be afraid of the power? do that which is good, and thou shalt have praise of the same:
For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil.
Wherefore ye must needs be subject, not only for wrath, but also for conscience sake." (Romans 13:1-5)
God has ordained the powers on Earth and the faithful should be subject to them and that these powers "beareth the sword" and act as a "revenger to execute wrath upon him that doeth evil" - and the faithful should not only be subject for wrath, but also for "conscience sake".
The governance of Man has been ordained by God and they can punish evil-doers - even by use of the sword (death) - and it is done as a form of "revenge" or inflicting retribution or justice - and for the sake of the conscience of the people - to preserve order.
"Then said Paul, I stand at Cæsar’s judgment seat, where I ought to be judged: to the Jews have I done no wrong, as thou very well knowest.
For if I be an offender, or have committed any thing worthy of death, I refuse not to die: but if there be none of these things whereof these accuse me, no man may deliver me unto them. I appeal unto Cæsar." (Acts 25:10-11)
As a Roman citizen - Paul appealed to Caesar's judgment - yet he claimed that he was willing to die if he had committed any offense worthy of that punishment.
Paul understood that no Man was above the laws of the land and that there were crimes that could cause the offender to be worthy of death and that execution could be an appropriate punishment.
God has ordained Man's governments to execute judgment to preserve order and to bring justice upon the offenders and to assuage the conscience of the offended - and this could be accomplished by execution when appropriate.
I personally believe that one of the causes of the many plights we have in our society stems the fact that we are refusing more and more to execute righteous judgment and put to death those that deserve it.