We can perceive a mixed bag of Ananias and Sapphira's sins involved in this tragedy. Acts 4:36-37 informs us of Barnabas' sacrificial gift for the well-being of the newly formed church. Pride and desire for acclaim motivated the couple to give a gift but without the honesty or sacrifice exhibited by Barnabas and others.
"Why has Satan filled your heart" (verse 3) is the equivalent of "Why have you dared?" They were free to give whatever percentage they set, for Peter says that the entire property sale price was under their control. Their sin lay in deceitfully alleging that the amount they gave was the whole of the sale price, when it was actually only a part. They deviously exaggerated their offering.
Some think this judgment was harsh, but Peter did not. He spoke of the sin as inspired of Satan, and the passage makes clear that both Ananias and Sapphira were fully aware of what they were doing (verses 2, 9). Conscious deceit is spiritually disastrous because trust is completely violated. They should have known better.
God interpreted their action as tempting Him, seeing how much they could get away with. Their way of reaching their goals is so opposed to the gospel that God could not allow it to go unchallenged; it would have set the whole mission of the church off course. Honesty and integrity are the standard of God's way of life. Sin is no light thing with God.
These people were living behind a deceptive façade, one similar to the idea that, if one keeps the front windows clean, it does not matter how dirty the back ones are. They allowed themselves to become tools working to destroy the family relationship of trust within the church. God forcibly reminded them and us that He will not abide that.
We must treat one another with fairness and loving kindness, or we will not be in His Family. Ananias and Sapphira are shocking reminders to us that we will not get away with deceitfully cheating or taking advantage of our brethren. God may not appear to be in the picture, but only the faithless have this blindness. The penalty will be paid—unless repented of, it is only a matter of time. Ananias and Sapphira paid quickly as a lesson to us.