From Latin intercedere, "to go between." Intercession is prayer on behalf of another — standing in the gap between the person prayed for and God, asking God to act for them. Distinguished from petition (prayer for oneself) by its focus. Biblical examples abound: Abraham for Sodom (Genesis 18:22-33); Moses for rebellious Israel (Exodus 32:11-14); Samuel for Israel (1 Samuel 7:5); Daniel for the exiled people (Daniel 9); Paul for the churches (Ephesians 1:15-23, 3:14-21, Colossians 1:9-14); Jesus for His disciples then and for every believer since (John 17). The intercessory role is explicitly assigned to all believers: "I urge that supplications, prayers, intercessions, and thanksgivings be made for all people" (1 Timothy 2:1).
Intercession is one of the deepest privileges of Christian life and one of the most neglected. Five observations. (1) Christ intercedes continually. "He always lives to make intercession for [us]" (Hebrews 7:25). "Christ Jesus is the one who died — more than that, who was raised — who is at the right hand of God, who indeed is interceding for us" (Romans 8:34). Every moment, our elder Brother brings our name before the Father. (2) The Spirit intercedes. "The Spirit helps us in our weakness. For we do not know what to pray for as we ought, but the Spirit Himself intercedes for us with groanings too deep for words" (Romans 8:26). Two divine Persons actively interceding for you right now — rest in that. (3) Believers intercede. Named lists of the churches and their situations (Ephesus, Colossae, Philippi) are embedded in Paul's letters. The modern version: keep a prayer list — names of family, friends, pastors, missionaries, government officials, the suffering, the lost — and actually pray for them. (4) Intercessory prayer moves heaven. "The prayer of a righteous person has great power as it is working" (James 5:16). The OT saints who interceded repeatedly saw God relent, forgive, restore, and act. The same God hears today. (5) A quiet ministry available to the weakest saint. A dying grandmother in a hospital bed can intercede for her grandchildren with as much effect as a traveling missionary can preach on the streets. In the economy of the Spirit, intercession may be the most fruitful ministry any Christian has.