From Pope Benedict XVI:
Faith leads Abraham to on a paradoxical journey. He will be blessed, but without the visible signs of blessing: he is promised he will become a great nation, but with a life marked by the barrenness of Sarah his wife; he is brought to a new home but will have to live there as a foreigner, and the only possession of the land that he will be allowed will be that of a piece of land in which to bury Sarah (cf. Gen 23.1 to 20). Abraham was blessed because, in faith, he was able to discern the divine blessing going beyond appearances, trusting in God's presence even when His ways appear mysterious to him.
What does this mean for us? When we say, "I believe in God," we say, like Abraham: "I trust you, I entrust myself to You, Lord," but not as Someone to run to only in times of difficulty or to whom to dedicate a few moments of the day or of the week. Saying "I believe in God" means grounding my life in Him, letting His Word guide each day, in the concrete choices without fear of losing something of myself. When, in the Rite of Baptism, we are asked three times: "Do you believe?" In God, in Jesus Christ, in the Holy Spirit, the Holy Catholic Church and the other truths of faith, the triple response is in the singular: "I believe," because it is my personal existence that reaches a turning point with the gift of faith, it is my life that must change, convert. Each time we participate in a Baptism we should ask ourselves how we live the great gift of faith every day.