Nobody likes to do something for someone else, and then have that person take all the credit for it. God doesn't either. Just as God gives seed to the sower, he gives blessings to those who give Him the credit. Proverbs 22:4 says "The reward for humility and fear of the Lord is riches and honor and life." And Luke 14:11 says "For all those who exalt themselves will be humbled, and those who humble themselves will be exalted.” So when we are blessed by God, we have two choices: take the credit for ourselves, in which case don't expect much else, or give God the honor and praise, in which case He will multiply our blessings because He knows He will be glorified through them.