If falling short of really and truly trusting God to do what He says, or to be in control doesn't.... I've got another one for you.
I find myself trying to take comfort in all the good things I'm doing. When I'm not feeling close to God, I catch myself thinking things like:
"I read my Bible everyday, therefore I'm a Christian"
"I went to church, and Sunday school all my life"
"I served at Bible camp as a teenager"
"I was baptized"
"I'm trying to sacrificially invest in other people's lives"
and one of the more recent ones
"I'm a missionary, I must be saved."
Psalm 51: 16-17 You do not delight in sacrifice, or I would bring it; you do not take pleasure in burnt offerings. The sacrifices of God are a broken spirit; a broken and contrite heart, O God, you will not despise.
Romans 3:21-25 But now a righteousness from God, apart from the law, has been made known, to which the Law and the Prophets testify.
This righteousness from God comes through faith in Jesus Christ to all who believe. There is no difference, for all have sinned and fall short of the glory of God, and are justified freely by his grace through the redemption that came by Christ Jesus.
God presented him as a sacrifice of atonement, through faith in his blood.
It's so easy to let the things we do creep in there as false qualifications for our salvation. In doing so, we are adding to the gospel and devaluing Christ's blood, the perfect sacrifice! It's idolatry of personal so-called accomplishments.
Also, I personally find this trap to be my ultimate joy-stealer. When I take my eyes of what Christ has accomplished for me, I am judgmental toward others, more critical, more self-righteous, more selfish! - period. And the more bitter I become because of how others have somehow failed me... what is this? What is this ugliness? It's plain old sin on my part! And it takes away any joy God has graciously given me to begin with.
If this isn't a reason to stay focused on the life of Christ and his sacrifice alone, I don't know what is. I don't want this to steal my joy anymore.