Can God Disappoint?
I know that some Christians struggle with a lyric in a song called "King of My Heart" that states that God is "never gonna let me down." Some believers cringe at that line because they can distinctly recall moments when they felt that they were disappointed in/by God.
If you find yourself cringing at that song try considering 1 Peter 2.6 (NASB) which says that "he who believes in God will not be disappointed." If you need a scriptural basis for the idea that God does not let His people down, this is certainly it.
The passage goes on to say that for those who "disbelieve", Jesus has become a "stumbling stone" and a "rock of offense," and that people stumble because they are disobedient to the word.
If you are more convinced of your disappointments in God than you are in His inability to disappoint, you may need to take time to assess whether you are a believer or a disbeliever. It may be time for a gut check to determine whether that painful, disappointing moment in your life with God was actually the result of your own disobedience to the word.
Based on this passage it appears that the distinction between those who are disappointed and offended by God and those that are never disappointed is in our pre-disposition to believe and obey or doubt and rebel. It really is a matter of perspective that causes us to interpret God's faithfullness correctly.
The ability to be disappointed in a God that is unable to disappoint is not an ability to celebrate, it is something to repent of.