Earthly disciples knowing heavenly visitors
Good afternoon. I will try to make this brief. I was born into a nominally Mormon home. For most of my growing years my parents never attended services, so I went by myself for many years. It was all I knew. After joining the Navy and much witnessing by several people, I finally read God's Word. I was convinced I was in the wrong place and resigned from the Mormon Church. I did the Bible Church thing for a while, then the base chapel and finally nothing for several years. I am now a member of an LCMS congregation. However, from time to time Mormon doctrine still rings in my head. Mormons believe in a pre-existence of our soul and when I read about the transfiguration, how would the disciples know who Christ was talking with having never met them before? It does not concern me to the point of doubting my faith, and I don't lose sleep over it, but it does make me wonder.
As you have come to know and believe, the Bible does not speak of the pre-existence of souls. That is one of many false teachings in the Mormon Church. It is good to read of your dissociation from that church.
The transfiguration accounts (Matthew 17:1-13; Mark 9:2-13; Luke 9:28-36) are truly amazing. Two Old Testament prophets appeared with Jesus, who revealed himself in all his glory as the Son of God. Peter, James and John were there to witness that glorious sight.
It was Peter who wanted to prolong the experience by erecting shelters for the Lord, for Moses and for Elijah. How did Peter and his companions recognize Moses and Elijah, since their earthly lives did not come anywhere close to overlapping? That is a question Scripture simply does not address. What we can do is rule out any kind of prior meeting of those individuals in a pre-existent soul setting.
We can also look forward to the time when we will see all the individuals in the transfiguration account—especially our Lord—and all fellow believers. There will be no need to try to prolong the experience. It will be forever!