1 John 5:16-17
"If any man see his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it. All unrighteousness is sin: and there is a sin not unto death."
The sins for which the death penalty is described in Scripture are quite plainly set out. God endorses the death penalty for "sins unto death".
Clearly the acceptance of a death penalty was still in effect in the NT church.
Acts chapter 5
1But a man named Ananias, with his wife Sapphira, sold a piece of property,2and kept back some of the price for himself, with his wife's full knowledge, and bringing a portion of it, he laid it at the apostles' feet.3But Peter said, "Ananias, why has Satan filled your heart to lie to the Holy Spirit and to keep back some of the price of the land?4"While it remained unsold, did it not remain your own? And after it was sold, was it not under your control? Why is it that you have conceived this deed in your heart? You have not lied to men but to God."5And as he heard these words, Ananias fell down and breathed his last; and great fear came over all who heard of it.6The young men got up and covered him up, and after carrying him out, they buried him.
7Now there elapsed an interval of about three hours, and his wife came in, not knowing what had happened.8And Peter responded to her, "Tell me whether you sold the land for such and such a price?" And she said, "Yes, that was the price."9Then Peter said to her, "Why is it that you have agreed together to put the Spirit of the Lord to the test? Behold, the feet of those who have buried your husband are at the door, and they will carry you out as well."10And immediately she fell at his feet and breathed her last, and the young men came in and found her dead, and they carried her out and buried her beside her husband.11And great fear came over the whole church, and over all who heard of these things.