What is intercessory prayer? It is the act of being a mediator to God, in prayer, on behalf of someone else. Pope St. Gregory the Great wrote: "when we are linked by the power of prayer, we, as it were, hold each other's hand as we walk side by side along a slippery path; and thus, but the bounteous disposition of charity, it comes about that the harder each one leans on the other, the more firmly we are riveted together in brotherly love."
And the Catechism of the Catholic Church (#2634-2636) sums it up like this: "Intercession is a prayer of petition which leads us to pray as Jesus did. He is the one intercessor with the Father on behalf of all men, especially sinners. He is able for all time to save those who draw near to God through him, since he always lives to make intercession for them. The Holy Spirit himself intercedes for us . . . and intercedes for the saints according to the will of God.
Intercession - asking on behalf of another - has been characteristic of a heart attuned to God's mercy. In the age of the Church, Christian intercession participates in Christ's, as an expression of the communion of saints. In intercession, he who prays looks not only to his own interests, but also to the interests of others, even to the point of praying for those who do him harm.
The first Christian communities lived this form of fellowship intensely. Thus the Apostle Paul gives them a share in his ministry of preaching the Gospel but also intercedes for them. The intercession of Christians recognizes no boundaries: for all men, for kings and all who are in high positions, for persecutors, for the salvation of those who reject the Gospel."
Below are two wonderful examples from Scripture of powerful intercessory prayer warriors:
Elijah, the Prophet:
For the People of God, the Temple was to be the place of their education in prayer: pilgrimages, feasts and sacrifices, the evening offering, the incense, and the bread of the Presence ("shewbread") - all these signs of the holiness and glory of God Most High and Most Near were appeals to and ways of prayer. But ritualism often encouraged an excessively external worship. The people needed education in faith and conversion of heart; this was the mission of the prophets, both before and after the Exile.
Elijah is the "father" of the prophets, "the generation of those who seek him, who seek the face of the God of Jacob." Elijah's name (meaning, "The Lord is my God,") foretells the people's cry in response to his prayer on Mount Carmel. St. James refers to Elijah in order to encourage us to pray: "The prayer of the righteous is powerful and effective." After Elijah had learned mercy during his retreat at the Wadi Cherith, he teaches the widow of Zarephath to believe in The Word of God and confirms her faith by his urgent prayer: God brings the widow's child back to life.
The sacrifice on Mount Carmel is a decisive test for the faith of the People of God. In response to Elijah's plea, "Answer me, O LORD, answer me," the Lord's fire consumes the holocaust, at the time of the evening oblation....Finally, taking the desert road that leads to the place where the living and true God reveals himself to his people, Elijah, like Moses before him, hides "in a cleft of he rock" until the mysterious presence of God has passed by. But only on the mountain of the Transfiguration will Moses and Elijah behold the unveiled face of him whom they sought; "the light of the knowledge of the glory of God [shines] in the face of Christ," crucified and risen.
In their "one to one" encounters with God, the prophets draw light and strength for their mission. Their prayer is not flight from this unfaithful world, but rather attentiveness to The Word of God. At times their prayer is an argument or a complaint, but it is always an intercession that awaits and prepares for the intervention of the Savior God, the Lord of history. (Catechism of the Catholic Church, #2581-2584)
Moses as Intercessor:
The prayer of Moses becomes the most striking example of intercessory prayer, which will be fulfilled in "the one mediator between God and men, the man Christ Jesus…the initiative is God's. From the midst of the burning bush he calls Moses. This event will remain one of the primordial images of prayer in the spiritual tradition of Jews and Christians alike. When "the God of Abraham, of Isaac, and of Jacob" calls Moses to be his servant, it is because he is the living God who wants men to live. God reveals himself in order to save them, though he does not do this alone or despite them: he calls Moses to be his messenger, an associate in his compassion, his work of salvation. There is something of a divine plea in this mission, and only after long debate does Moses attune his own will to that of the Savior God. But in the dialogue in which God confides in him, Moses also learns how to pray: he balks, makes excuses, above all questions: and it is in response to his question that the Lord confides his ineffable name, which will be revealed through his mighty deeds.
Thus the Lord used to speak to Moses face to face, as a man speaks to his friend. Moses' prayer is characteristic of contemplative prayer by which God's servant remains faithful to his mission. Moses converses with God often and at length, climbing the mountain to hear and entreat him and coming down to the people to repeat the words of his God for their guidance. Moses "is entrusted with all my house. With him I speak face to face, clearly, not in riddles," for "Moses was very humble, more so than anyone else on the face of the earth."
From this intimacy with the faithful God, slow to anger and abounding in steadfast love, Moses drew strength and determination for his intercession. He does not pray for himself but for the people whom God made his own. Moses already intercedes for them during the battle with the Amalekites and prays to obtain healing for Miriam. But it is chiefly after their apostasy that Moses "stands in the breach" before God in order to save the people. The arguments of his prayer - for intercession is also a mysterious battle - will inspire the boldness of the great intercessors among the Jewish people and in the Church: God is love; he is therefore righteous and faithful; he cannot contradict himself; he must remember his marvelous deeds, since his glory is at stake, and he cannot forsake this people that bears his name. (Catechism of the Catholic Church #2574 – 2577)