Go back and read Acts 4:32-5:11 to get the background about Ananias and Sapphire:
Acts 4:
32 And the multitude of them that believed were of one heart and of one soul: neither said any of them that ought of the things which he possessed was his own; but they had all things common.
33 And with great power gave the apostles witness of the resurrection of the Lord Jesus: and great grace was upon them all.
34 Neither was there any among them that lacked: for as many as were possessors of lands or houses sold them, and brought the prices of the things that were sold,
35 And laid them down at the apostles' feet: and distribution was made unto every man according as he had need.
36 And Joses, who by the apostles was surnamed Barnabas, (which is, being interpreted, The son of consolation,) a Levite, and of the country of Cyprus,
37 Having land, sold it, and brought the money, and laid it at the apostles' feet.
In Acts 4:32 we see that all the believers shared all of their possessions amongst each other. And according to Acts 4:34 no one lacked.
Then we have believers selling their lands and possessions and bringing the money to the apostles. Again, distribution according to need. Then Joses (Barnabas) sold land and brought the money to the apostles.
However, when Ananias and Sapphira sold their possessions, they acted like they were doing as the believers in Acts 4 (giving the full amount of sales proceeds). But Ananias and Sapphira kept back part (Acts 5:2).
That was their downfall.
Acts 5:
1 But a certain man named Ananias, with Sapphira his wife, sold a possession,
2 And kept back part of the price, his wife also being privy to it, and brought a certain part, and laid it at the apostles' feet.
3 But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land?
4 Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God.
5 And Ananias hearing these words fell down, and gave up the ghost: and great fear came on all them that heard these things.
6 And the young men arose, wound him up, and carried him out, and buried him.
7 And it was about the space of three hours after, when his wife, not knowing what was done, came in.
8 And Peter answered unto her, Tell me whether ye sold the land for so much? And she said, Yea, for so much.
9 Then Peter said unto her, How is it that ye have agreed together to tempt the Spirit of the Lord? behold, the feet of them which have buried thy husband are at the door, and shall carry thee out.
10 Then fell she down straightway at his feet, and yielded up the ghost: and the young men came in, and found her dead, and, carrying her forth, buried her by her husband.
Acts 5:4 makes it clear that they could have kept however much of the sales proceeds they wanted, as long as they didn’t act as if they were giving 100%.
tangled web ... folly of man