almost hear the counting going on right about now...)
There are two primary reasons why this happens:
No. 1: We do or do not do something that prevents, modifies, or delays what God promised. He has given us authority to do that. It is called "free will"--think of accepting or refusing a gift.
No. 2: We have not reached the time of the promise's fulfillment. In other words, "It's not over yet."
Brothers, as an example of patience in the face of suffering, take the prophets who spoke in the name of the Lord. As you know, we consider blessed those who have persevered. You have heard of Job's perseverance and have seen what the Lord finally brought about. The Lord is full of compassion and mercy. (James 5:10-11 NIV)