John Piper on relativism in Think:
Let’s begin our assessment of relativism with an interaction between Jesus and some classic practical relativists—not self-conscious, full-blown relativists, just de facto relativists, which are the most common kind, prevalent in every age, not just this one. It will be helpful to watch Jesus meet the relativists. Consider Matthew 21:23–27:
And when he entered the temple, the chief priests and the elders of the people came up to [Jesus] as he was teaching, and said, “By what authority are you doing these things, and who gave you this authority?” Jesus answered them, “I also will ask you one question, and if you tell me the answer, then I also will tell you by what authority I do these things. The baptism of John, from where did it come? From heaven or from man?” And they discussed it among themselves, saying, “If we say, ‘From heaven,’ he will say to us, ‘Why then did you not believe him?’ But if we say, ‘From man,’ we are afraid of the crowd, for they all hold that John was a prophet.” So they answered Jesus, “We do not know.” And he said to them, “Neither will I tell you by what authority I do these things.”
Look carefully at how the chief priests and elders deal with truth. Jesus asks them to take a stand on a simple truth-claim: either John’s baptism is from heaven or from man. Declare what you believe to be the truth.
So they ponder: “If we say that John’s baptism is from heaven, then we will be shamed because Jesus will show that we are hypo crites. He’ll ask why we haven’t believed in John’s message. He’ll point out that we say we think his baptism is from heaven, but we don’t live like it. We will be shamed before the crowds.
“But if we say that John’s baptism is from man, we may be harmed by the crowd, because they all believe he was a prophet. There could be some mob violence against us. Therefore, since we don’t want to be shamed, and we don’t want to be harmed by a mob, let’s not say that either of these options is true. We will simply say that we don’t know the answer.”
What are we to make of this? This is not full-blown relativism. Rather, what we see here are the seeds of relativism. Here is the way the depraved mind works. Let’s make the connection with chapters 4 and 5 on the role of thinking in the rise of faith. What we saw there was that the human mind, apart from transforming grace (Rom. 12:2; Eph. 4:23), is depraved (1 Tim. 6:5) and debased (Rom. 1:28) and hard (2 Cor. 4:4) and darkened and futile (Eph. 4:17–18). But it was created by God to discover the truth and respond to the truth in trusting God and loving people.
But Matthew 21:23–27 is a picture of what has become of the human mind taken captive by sin. The elders and chief priests do not use their minds to formulate a true answer to Jesus’ question. How do they use their minds? Oh, they use them carefully. What we see here is not people who should be using their minds in the service of truth but don’t use them at all. No. They use them incisively, and Matthew lets us see the inner workings of such thinking. Everybody thinks. The difference is whether we think in service of the truth or in the way the chief priests and the elders think.
Jesus’ response is explosively relevant for how we deal with such duplicity. He says, “Neither will I tell you by what authority I do these things.” In other words, “This conversation is over. I don’t have serious conversations with people like you.” Jesus abominates that kind of arrogant, cowardly prostituting of the glorious gifts of human thinking and human language.
People don’t embrace relativism because it is philosophically satisfying. They embrace it because it is physically and emotionally gratifying. It provides the cover they need at key moments in their lives to do what they want without intrusion from absolutes.