Liz from Florida asked: Does Malachi 3:8 obligate me to tithe?
The verse you reference says this:
 Will man rob God? Yet you are robbing me. But you say, ‘How have we robbed you?’ In your tithes and contributions. (Malachi 3:8 ESV)
And then in verse 10 he says:
 Bring the full tithe into the storehouse, that there may be food in my house. And thereby put me to the test, says the LORD of hosts, if I will not open the windows of heaven for you and pour down for you a blessing until there is no more need. (Malachi 3:10 ESV)
Liz, I want to introduce you to the phrase: “grace giving.”
Those Old Testament passages were commands given to Israel. Many pastors who use the Old Testament to talk about the need for tithing usually refer to a 10% tithe. The problem is, if you read the Old Testament fully, you discover that there were several tithes that the people of Israel were to give. When you add them all up, they were obligated to give an amount closer to 25% of what they had. And in addition to that, they had grace offerings that were given over and above what was required.
At the end of the gospels, Jesus ascended to heaven and the church was established. The church is not Israel. The church is not obligated to follow the Old Testaments' system of sacrifices and tithes and ceremonies. God gave the church a new model for giving. That model is found in 2 Corinthians 9:7
 Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver. (2 Corinthians 9:7 ESV)
This is the principle of grace giving. Each of us is to determine before God what we will give, and we do so cheerfully. Some people might give 10%. Others might give 12%, 20%, or 5%. The key truth regarding grace giving is to give as God leads you, and to pray for a generous spirit.
Thanks for your question, Liz.