‘But Peter said to her, “How is it that you have agreed together to try the Spirit of the Lord? Behold, the feet of those who have buried your husband are at the door, and they will carry you out.” '
Then Peter challenged her as to how she and her husband could have thought of testing the Spirit of the Lord out in this way, and informed her that those who had just buried her husband were at the door, and would carry her out as well. Once again the Spirit of the Lord is spoken of as a person.
We must not see Peter as the one who passes the judgment. He simply passes on God's judgment. What happened was not Peter's doing, it was God's, a sacred if awful example, given as a warning to all.
‘You have agreed together to try the Spirit of the Lord.' The key Old Testament texts which deal with putting God to the test are Exodus 15:25; Exodus 16:4; Exodus 17:2 and Deuteronomy 16:6. Significantly they all deal with times when there was a need to satisfy physical requirements, and all refer to the fact that they were not prepared to trust God. That was why Jesus refused to put God to the test (Matthew 4:7; Luke 4:12). He did trust God. So underlying the sin of Ananias and Sapphira was unbelief and an unwillingness to trust God. And this at a time when such trust was vital to the continuation of the newborn church.