First, religious pluralism eliminates the possibility of specific, historical divine revelation.
"According to orthodox Christianity, God begins with particular persons and events—Abraham or the Incarnation. He does have the universal in mind, seeking to bless all the families of the earth (Genesis 12:1–3). Like ripples from a stone tossed into a pond, the Christian mission to the world flows from the Incarnation; the gospel offers salvation to all through God’s enabling Spirit. Pluralism, however, leaves us with a property-less, content-less Ultimate Reality. How then do we need to respond to It? Do we need to love It, or pray to It, or just live ethically? Can we know It even exists?"
Second, religious pluralism is logically just as exclusivistic as the Christian — or any other faith.
Third, despite its claims, religious pluralism is geographically-limited—which is the very charge made by pluralists against religions like Christianity (“If you were born in Saudi Arabia, you’d be a Muslim”—a view known as the “geography objection”).
Fifth, the Christian’s motivation to live humbly, gratefully, graciously, and self-sacrificially is connected to Jesus’ authority as God’s Son. "According to the New Testament, Jesus does not have authority just because we find ourselves agreeing with his moral teaching. Rather, it is Jesus’ unique status as God’s Son that serves as the source and locus of his authority—regardless of whether we happen to agree with his teaching! (Thus we should reject the bumper sticker theology that affirms, “God said it. I believe it. That settles it.” No, God/Jesus said it. That settles it whether I believe it or not!). If Jesus is not the unique Son of God but a mere man, then the Christian’s motivation will lose much of its force. If Jesus is not God incarnate, this undercuts historic Christianity’s claims and seriously undermines our devotion to Christ. This is a pragmatic consideration, yes, but the Christian faith is bound up with historical events such as Jesus’ death and resurrection. If these never occurred, then Paul urges us to consider hedonism since a merely earthly hope in Christ is delusional (1 Corinthians 15:32)".
Sixth, if Jesus is God’s Son, this effectively undermines religious pluralism. Consider the following subpoints:
(a) Jesus was different from the founders of other great religions.
(b) The earliest Christians — fiercely monotheistic Jews — bore witness to an exalted Jesus who shared in the divine identity.
(c) Jesus rose from the dead in confirmation of his claims.
"In the end, religious pluralism will not let Jesus be Jesus. If it did, it would undermine itself".