Are Baptism and the Supper symbols or realities?
It’s a false question. Words are symbols, but we know that words have enormous power for good or evil. A flag, a handshake, a kiss, a poster, are also symbols but they are clearly as real as stars and snakes and salamanders. So, to say that the Church’s bread, wine, and water are symbols is not to say that they are without value or power, or that they lack ‘reality.’ It is merely to say that whatever power they have is the kind of power that symbols have, and not the kind of power that a combustion engine or a nuclear power plant has. It is to say that whatever reality they have is the kind of reality that symbols always have. Theology goes into the ditch when it treats symbols as if they were something other than symbols. And at the bottom of the ditch is Christianity.
So, the opposition of symbol and reality is a false antithesis.
We can arrive at the same destination along another pathway. What is baptism? Not water only, not only water poured. Baptism is water poured on a person in obedience to Christ and by His authorization. What is the Supper? It is not just bread and wine, and not just eating of bread and wine. It is eating bread and wine by members of Christ’s body at Christ’s invitation. Christ’s authorization and definition and invitation make all the difference.
Baptism is not a “symbol” of someone becoming a disciple. Because Jesus designated it as such, the symbol is his “becoming-a-disciple.” It is not a picture of a man being joined in covenant with Christ; it is a man being joined in covenant to Christ.
The Supper is not a symbol of a meal with Jesus. The bread and wine are symbols of Christ’s body and blood, but because Jesus promised to be with us at the table, this symbolic meal is a meal with Jesus. By eating the symbols, we are partaking in the reality.
Symbol or reality? It is a false question.
-Peter Leithart, Against Christianity, pp.85,86