One of the things we cope with daily is the tension between our feelings and what is true. Feelings are given to us by God, but held within our flesh, they may not always represent what is true. Feelings are fleeting, changeable, and often unreliable. Brownback has something to say about this:
Unpredictable and unstable as they are, if we allow our feelings to determine our well-being, rather than allowing our standing in Christ to determine our feelings, we are going to be anxious about everything all of the time.
Joy and peace are characteristics of the Christian life, but inevitably there will be times, whether through sin or through some hardship or through just being human, when joy and peace elude us. But the presence or absence of good feelings is no measure of God's favor. Christ is the only measure. If we look to our feelings as a barometer of how well we are doing with God, using them to measure whether he is pleased with us, then our faith will be shaken during times when feelings of joy and peace are hard to find.
How wonderfully freeing it is to flip-flop our feelings with faith -- and we can do it because it is God's will that we do so. Our relationship with God and all the good that accompanies it are secure in Christ, no matter how we feel.