Praying to the Saints
Whether asking the saints to pray for us is idolatry, or the communion of the living Body of Christ.
The objection, at its strongest:
Catholic devotion to the saints looks like the very thing Scripture forbids. Catholics bow before statues and pray to dead human beings, seeming to give creatures honors that belong to God alone. There is "one mediator between God and men, the man Christ Jesus": so why pray to anyone else? At best this is an unbiblical distraction; at worst it is idolatry dressed in piety.
The response:
The objection turns on a single confusion, and once it is cleared the rest follows. Catholics do not worship the saints. The Church draws a hard line between adoration (latria), which belongs to God alone, and honor (dulia), which we rightly give to holy people: the same kind of honor Scripture commands us to give parents, elders, and the faithful, only raised to its highest pitch. To venerate a saint is not to treat them as a god; it is to admire what God has done in them, exactly as we honor a hero without confusing him with the cause he served. A statue or icon is not worshiped any more than a photograph of a loved one is; it is an aid to memory and affection, no different in kind from the images God Himself commanded for the Temple and the Ark.
Praying to the saints is likewise not what it sounds like. To pray to a saint, in the old sense of the word, is simply to ask: to request their prayers, as you might ask a friend to pray for you.
The one mediator is not diminished. Christ is the sole mediator of redemption: no saint adds anything to His saving work. But Scripture constantly urges Christians to intercede for one another, and no one thinks asking a friend to pray rivals Christ's mediation. Asking a saint is the same act, directed to a Christian who happens to be more alive than we are, not less.
The saints are alive in Christ. "God is not the God of the dead, but of the living." Those in glory are not gone; they are more fully alive, and Scripture pictures them aware of and concerned with what happens on earth: the saints in heaven offering the prayers of God's people before the throne. To ask their intercession is to take the communion of saints seriously as a real communion, unbroken by death.
Their holiness is God's work, on display. To honor a saint is never to praise a self-made hero; it is to praise what grace accomplished in a person who let it. Every saint is a window, and the light that shines through is Christ's. Honoring them is one of the ways the Church says, out loud, that He really does make people holy.
Why it belongs to the Catholic claim. These devotions are not late accretions bolted onto the gospel. Prayer to the martyrs and confidence in the intercession of the saints are visible in the earliest Christian worship — in the catacombs, the Fathers, and the liturgy — long before the divisions of later centuries. A Church that had lost this would look less like the early Church, not more. Far from competing with Christ, the honor given to the saints is simply what it looks like to believe that death does not sever the Body He has joined together.