Was the New Testament gift of prophecy the ability to tell the future?
No. The New Testament gift of prophecy was not primarily the ability to tell the future; it was the gift of speaking forth the Word. While the word 'prophesy' in Scripture can mean either telling the future or speaking forth the Word, the early church's gift was for speaking forth the Word because the printed page had not yet come.
Les explains that in Scripture the word 'prophesy' can mean either telling the future or simply speaking forth the Word. He points out that when the Apostolic Church had men with the gift of prophecy, it was not that they had a gift for telling the future, but they had a gift for speaking forth the Word. That gift was given to the early church because the printed page had not yet come out. Les also applies this same distinction to the two witnesses, saying they are not necessarily going to tell the future, but they will speak forth the Word as His witnesses.