Postmodern Christians who dismiss the veracity of propositional truth like to cite John 14:26 where Jesus said, “I am the way, the truth, and the life.” “Jesus is the truth,” they say, “not doctrinal statements. Jesus is the only truth that matters.”
This way of interpreting Jesus’ statement presumes that Jesus is saying He is identical to the truth, such that to speak of the truth is to speak of Jesus. Linguists call this the “is of identity.” An example of this use of “is” would be the statement, “Barack Obama is the president of the United States.” There is an identity relationship between the man Barack Obama and the office of the president of the United States. Clearly that’s not the kind of “is” Jesus is referring to. When Jesus says he is the truth, he is not making an identity statement such that “Jesus = the truth,” otherwise, “to say that ‘2+2=4’ is true is to say that ‘2+2=4’ is Jesus. In other words, Jesus is claiming to be a mathematical statement.”
Jesus’ use of is is what we call the “is of predication.” This is when you predicate a property of someone or something. For example, when we say “grass is green,” we aren’t saying that grass and green are identical, but that green can be predicated of the grass. Jesus is truth in the sense that He can be described as being true. There is no falsehood in Him. He embodies everything that is true. For that to be true (no pun intended), propositional truth must exist since you cannot predicate truth to Jesus unless there are truths that exist in the first place.
Richard B. Davis and W. Paul Franks, “On Jesus, Derrida, and Dawkins,” in Philosophia Christi, Vol. 16, Number 1, 2014, 185-191, 189.