As we reach the end of the prayers, we express the confident joy that God has accepted our prayers.
In general, prayers reflect two conflicting emotions—love/closeness and awe/distance. By definition, praying involves forging these two together, so they become one.
Certainly, at the outset, we may feel a sense of deep alienation and a great desire to move closer, but as we progress in prayer, a greater sense of closeness arises. Perhaps on all levels of prayer, there is a constant vacillation of emotions, but surely at the inception we feel more distance, while toward the end, we feel closer.
Having traveled on the path of prayer, and having arrived at the end of the musaf morning service, we confidently sing out our conviction of belief. This, in itself, ensures that our prayers will be answered for good, for blessings and for happiness.