"Bring...(the whole tenth of your income)." Malachi 3:10 AMP
When this passage starts talking about tithing it refers to robbing God. I believe it is talking about God being robbed of blessing us through our obedience. God really does what to bring unlimited blessing to our lives.
Whether you believe tithing to be an Old Testament law or a New Testament truth, one thing is certain, giving God the first tenth of your income demonstrates that He's first in your life. To those who practice tithing, God promises two things:
(1) His blessing. God said He will "Open for you the windows of heaven and pour out for you such a blessing that there will not be room enough to receive it" (Mal 3:10 NKJV). A farmer, who was a faithful tither, was prospering while others around him were barely getting by. When one of his neighbors asked, "What's your secret?" he replied, "No secret, I just shovel it into God's bin and He shovels it back into mine - but God's got a bigger shovel!" By tithing, you partner with God. Think what God's blessing could mean to your business, your family, your ministry or your future - your possibilities are out of sight!
(2) His protection. "I will rebuke the devourer...he shall not destroy" (Mal 3:11). "What's the devourer?" you ask. Anything that devours your blessings. The dishwasher breaks down for the third time in a month. The kids are ill and have to be taken to the doctor all the time. The day after the warranty runs out on your car, the transmission goes. One of the Hebrew words for tithe is charam, which means "marked for destruction." Your tithe literally becomes a force in the hand of God to destroy the works of the enemy. It puts a hedge of protection around you. "Is God after my money?" you ask. No, He's after your lack! He wants you to be blessed and protected every day of your life.