Do you believe?
No matter what I say I believe about the gospel, I don't believe what I say I believe. Let me explain. Galatians chapters 3&4 tell me that, because of Christ's immense love for me - a love he proved on the cross - I am no longer a slave. Because Christ's death purchased my freedom, I can walk right into the throne-room of God Almighty and call him Abba Father (daddy). I can do that, not because I did a bunch of good things to make him happy with me but because Christ, God's perfect son, did a bunch of good things for me. In fact, no matter what I did yesterday or what I'll do tomorrow, good or bad, my relationship with God is unchanged because Jesus remains unchanged for me. His ridiculously outrageous grace toward me is the glue that holds me tight to him (not my good attitude or good intentions).
YET (and this is so sad for a genuine follower of Christ like me), many mornings I awake sure that God is disappointed in me; sure that the habits I can't break and the unholy thoughts I think separate me from him; sure that, if I just try harder today, I have what it takes in side of me to make God happy.
Hence my initial comment: No matter what I say I believe about the gospel, I don't believe what I say I believe. Because if I did, I wouldn't be doubting God's love. If I did, I wouldn't, via my thoughts and actions, question whether Christ's sacrifice for me was good enough (believing I could somehow help). If I believed what I say I believe, I'd wake each morning knowing that Jesus is absolutely in love with me and longs for me to do nothing more than bask in that love. The rest will take care of itself as I come to know that I know how much he loves and treasures me (because, knowing this produces a change in my behavior).