"But a man named Ananias, with the consent of his wife Sapphira, sold a piece of property; with his wife’s knowledge, he kept back some of the proceeds, and brought only a part and laid it at the apostles’ feet.‘Ananias,’ Peter asked, ‘why has Satan filled your heart to lie to the Holy Spirit and to keep back part of the proceeds of the land? While it remained unsold, did it not remain your own? And after it was sold, were not the proceeds at your disposal? How is it that you have contrived this deed in your heart? You did not lie to us but to God!’ Now when Ananias heard these words, he fell down and died. And great fear seized all who heard of it. The young men came and wrapped up his body, then carried him out and buried him.
"After an interval of about three hours his wife came in, not knowing what had happened. Peter said to her, ‘Tell me whether you and your husband sold the land for such and such a price.’ And she said, ‘Yes, that was the price.’ Then Peter said to her, ‘How is it that you have agreed together to put the Spirit of the Lord to the test? Look, the feet of those who have buried your husband are at the door, and they will carry you out." Immediately she fell down at his feet and died. When the young men came in they found her dead, so they carried her out and buried her beside her husband" (Acts 5:1-10).
It seems antithetical to the love of Christ. Was the Holy Spirit the punisher?
It is an absolute law of Spirit that choices have consequences. In this case, Ananias and Sapphira had made a vow, along with the other disciples, to pool their resources fully. When they later decided to withhold a portion of their good, that negative choice resulted in negative consequences. It's important to note, I think, that they are not put to death as punishment. They died when their deception was discovered. In a sense, they chose the punishment they felt they deserved.