Deuteronomy 14:22-23 You must set aside a tithe of your crops -- one tenth of all the crops you harvest each year. Bring this tithe to the designated place of worship -- the place the Lord your God chooses for his name to be honored -- and eat it there in his presence. This applies to your tithes of grain, new wine, olive oil, and the firstborn males of your flocks and herds. Doing this will teach you always to fear the Lord your God.
First we have to understand what fear of the Lord actually means... wiki.answers.com says this:
The word 'fear' as used, especially in the Authorised version (King James version) of the Bible is a perfect example of how words have changed over time and now have a slightly different meaning.
The word 'fear' as in 'we should fear God' does not mean that we should be scared of him, as the modern meaning of the word should suggest. Instead, the word 'fear' means 'a healthy respect for', or to 'stand in awe of' him - or, even more accurately, a mixture of the two.
Notice that the people took their best to God..then they ate what they took. God gave it back to them...He gave them back the best that they gave to God!! This was not food they could sell ... it was a gift to God... a gift that He gives back to them. So God, when the people gave Him their best, gave the people back their best. He actually made sure that the people had the best of what the raised for themselves!! That is so special. When we give to God our tithe, our ten percent... God gives us back the best that that ten percent could get us!! God protects that ten percent for us!!
Then notice what happens after that, "Doing this will teach you always to fear the Lord your God." If we used the definition in place of fear this verse would say, "Doing this will teach you to always have respect for and stand in awe of God." When we tithe.. give our first ten percent... God will bless us so much that we stand in awe of Him!!
Micah 3:10 tell us this, "Bring all the tithes into the storehouse so there will be enough food in my Temple. If you do," says the LORD of Heaven's Armies, "I will open the windows of heaven for you. I will pour out a blessing so great you won't have enough room to take it in! Try it! Put me to the test!" Look here it says put me to the test and I will show you what giving to me will do for you!!
God does not, can not go back on His word... I challenge you to tithe your ten percent and see what amazing things happen in your life!!