The testimony of two nations] In the justice of God, none are to be condemned for failure to accept revealed truth when the reality of the revelation is not clearly established.
The truths of salvation do not stand alone.This principle, though well known to ancient Israel, is never mentioned in the theologies of modern Christendom. Yet it was by virtue of this principle that John the Baptist was called to prepare the way for Christ and that both John and Christ were required to seal their testimonies with their blood. In like manner, it was this principle that required that Hyrum Smith be in Carthage to mingle his blood with that of the Prophet Joseph. The same principle required that two others be with them (John Taylor and Willard Richards) and that both survive so that we might have an unimpeachable account of the martyrdom. It was for this reason that Joseph Smith was never alone when priesthood or keys were restored and that missionaries are sent out two by two.