The Old Testament proclaims the mercy of the Lord by the use of many terms with related meanings; they are differentiated by their particular content, but it could be said that they all converge from different directions on one single fundamental content, to express its surpassing richness and at the same time to bring it close to man under different aspects. The Old Testament encourages people suffering from misfortune, especially those weighed down by sin - as also the whole of Israel, which had entered into the covenant with God - to appeal for mercy, and enables them to count upon it: it reminds them of His mercy in times of failure and loss of trust. Subsequently, the Old Testament gives thanks and glory for mercy every time that mercy is made manifest in the life of the people or in the lives of individuals.
Connected with the mystery of creation is the mystery of the election, which in a special way shaped the history of the people whose spiritual father is Abraham by virtue of his faith. Nevertheless, through this people which journeys forward through the history both of the Old Covenant and of the New, that mystery of election refers to every man and woman, to the whole great human family. "I have loved you with an everlasting love, therefore I have continued my faithfulness to you."56 "For the mountains may depart...my steadfast love shall not depart from you, and my covenant of peace shall not be removed."57 This truth, once proclaimed to Israel, involves a perspective of the whole history of man, a perspective both temporal and eschatological.58 Christ reveals the Father within the framework of the same perspective and on ground already prepared, as many pages of the Old Testament writings demonstrate. At the end of this revelation, on the night before He dies, He says to the apostle Philip these memorable words: "Have I been with you so long, and yet you do not know me...? He who has seen me has seen the Father."59