God's timing

So I was reading a little this morning and once again came across a verse in Genesis that always makes me cringe for some reason...

Genesis 15:13-14
¹³ God said to Abram, "Know for certain that your descendants will be strangers in a land that is not theirs, where they will be enslaved and oppressed four hundred years. ¹⁴ "But I will also judge the nation whom they will serve, and afterward they will come out with many possessions."

This is part of the "promise" that is made to Abram. Basically that he will be fine, but his people will be enslaved for FOUR HUNDRED years. It seems that God's concept of time is much different than ours. Did it really take that long for the children of Israel to deserve deliverance? Of course I know all the traditional answers, but sometimes I think it is good to simply ask a question without attempting to provide an answer.

This verse does place some perspective on times when I have felt like God was taking too long to answer a particular prayer in my life!