Epoptai is the Greek word for eyewitnesses, from epoptes (singular). It is a hapax. Hapax is the Greek word for "once." That is, epoptai appears only once in the New Testament, in 2 Peter 1:16. (Note: similar words appear in 1 Peter 2:12 and 3:2.)
In presenting Christian evidences, I often comment on 2 Peter 1:16. Skeptics tend to assume the first Christians were gullible -- that they were somehow victimized by a grand scheme and defrauded of the true joys of the world by the curse of Christianity. But Peter wrote, "We did not follow cleverly invented stories when we told you about the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty." In other words, "No one duped us. The facts have been empirically verified!"
In fact, throughout the New Testament there is considerable emphasis placed on the concept of the validity of eyewitnesses. "Have I not seen Jesus our Lord?" asked Paul in 1 Corinthians 9:1. The prologue of 1 John also emphasizes the weight of eyewitness testimony. If the early Christians were staking their lives on a vague rumor, they are much to be pitied. "Quite the contrary," they would have collectively affirmed. "We've seen it with our own eyes, and it is true; we believe it, and so should you."
Even though we did not live at just the right time and place to be eyewitnesses of all the remarkable events surrounding Jesus' life, we can still believe the testimony of others (John 20:19-31). In a different sense perhaps to our first century comrades, we too are called to be epoptai.
