Acts 5:12a, 13b
If you have time read Acts 4 and 5 (http://www.biblegateway.com/passage/?search=Acts%204-5&version=MSG). I've put a link to the Message Version at Biblegateway. If you go there you can choose a different verse if you don't like that one.
Anyway, they are pretty scary chapters. They are full of miracles but a couple people die because they lied to the early Church about how much they got for a piece of land.
This seems pretty harsh but we have to take the whole story in context. Right before Ananias and Sapphira (the two who lied and were killed by God) gave the disciples money, we read about Barnabas doing the same thing. Yet, He gave the whole purchase price. He held nothing back.
This couple holds something back. Now Peter tells them there was no problem holding something back -- not giving the disciples all the money. It was their money. The problem was is that they wanted to look like they gave it all so they lied about what they got for the land. They wanted to operate in the power of the Holy Spirit that was on the disciples. They wanted God's power but they weren't willing to do it God's way. They were giving to get.
God never demands we give anything. He wants us to give cheerfully.