1.) Several verses come to mind.
- The mouths of fools are their undoing, and their lips are a snare to their very lives (Pr 18:7). The tongue has the power of life and death, and those who love it will eat its fruit (v. 21).
- For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord (Ro 6:23).
- But godliness with contentment is great gain. For we brought nothing into the world, and we can take nothing out of it. But if we have food and clothing, we will be content with that. Those who want to get rich fall into temptation and a trap and into many foolish and harmful desires that plunge people into ruin and destruction. For the love of money is a root of all kinds of evil. Some people, eager for money, have wandered from the faith and pierced themselves with many griefs (1 Ti 6:10).
What happened to Ananias and Sapphira reminds me of when Simon the sorcerer tried to buy the gift of God with money. Long story short, Peter gave Simon a strong reprimanded, “May your money perish with you, because you thought you could buy the gift of God with money! (Ac 8:20). Both these incidents had to do with the value that these people placed on money. The couple valued money above the truth. Simon thought that money could buy the gift of God. In other words, they valued (or loved) money rather than "godliness with contentment." In the case of Ananias and Sapphira, that misplaced valued costed them their lives.
2.) It's implied that God killed them. Much like it's implied that God killed Nabal. That has something to do with the fear of God. That's discussed a lot in the OT. Many NT Christians claim that the fear of God is an OT principle that's not really relevant anymore because of Jesus and grace. Jesus and grace are a central theme on the NT. However, what happened to Ananias and Sapphira is a lone reminder that even in the dispensation of grace the fear of God is still relevant and applicable.
And great fear came over the whole church, and over all who heard of these things (Acts 5:1-11). Whole church applies to us too because we are the NT church, lest we forget. May we bridle our tongues and not love money.