No doubt your friend is sincere in his beliefs, but I'm afraid he has misunderstood the unique nature of the Christian faith.
Why is the Christian faith different from other religions? The Bible tells us that Christianity is unique because Jesus Christ was unique—and Jesus Christ was unique because He was God in human flesh. He wasn't simply a great religious figure or a profound teacher, nor was He only a saintly or godly man. He was more than that: He was God in human form! Out of all the religious teachers and philosophers who have ever walked the earth, only Jesus could say, "I and the Father are one" (John 10:30). He proved it by coming back to life on the third day after His death.
But Christ was unique for another reason: Only He laid down His life as the perfect and final sacrifice for our sins. Our greatest need is to have our sins forgiven and cleansed—and this is possible only because Christ died for us. Now by faith in Him we can be forgiven, and we can have the hope of heaven.
Pray for your friend, that he won't let pride, or anything else, blind him to his need of Christ. The greatest discovery we can ever make is that God loves us, and that Christ died for us. May this become his experience—and yours as well.