What is a tithe? A tenth part of one's annual income contributed voluntarily, especially for the support of the clergy or church. Well that's the dictionary's definition but it's really a way of giving back to the Kingdom to show your gratitude to God. It furthers the work of the gospel here in our local churches.
Don't you think you've already got a good deal with all the blessings you've received? Some people want to give little or nothing back in return. Do you think that because tomorrow is tax day that you've given enough? The Bible says 'So give back to Caesar what is Caesar’s, and to God what is God’s.” The IRS nor does God accept a groupon or substitutes. Cain wanted to give an alternative to a blood offering but that was unacceptable to God.
It's important in this age of 'getting a free ride in life' kind of thinking to teach kids at a young age to not just be takers but more importantly to be givers of gratitude.