Does the mount of transfiguration demonstrate that the dead are conscious?
The organization known as the "Iglesia Ni Cristo" claims that when the dead await judgment, they remain unconscious. However, does the appearance of Moses and Elijah on the mount of transfiguration contradict this teaching?
When we examine the passage, we see that it contradicts the INC's teaching.
Moses and Elijah spoke with Jesus.
On the mount of transfiguration, we are told that Moses and Elijah spoke with Jesus.
Luke 9:30 And behold, two men were talking with him, Moses and Elijah,
Though neither continued living on this earth, they spoke with Jesus. Notice that Jesus also spoke with them, meaning that the one the disciples were present with (Jesus) considered Moses and Elijah to be sentient/conscious entities.
Moses had died.
While Elijah went directly to heaven (2Ki 2:11), and it is not recorded that he died, it is clear from the Bible that Moses died (Deu 34:5). Some argue that he received received a final resurrection, but there is no clear Biblical statement that says so. Moreover, the INC has not taken a clear position on this in any accessible literature. If they wish to argue that Moses already received a final resurrection, let them do so publicly.
A "vision" is often something that occurred.
The INC may object and claim that Jesus called this a vision, so therefore it is not a real event. The problem with this is that the word "vision" can be used to refer to a real event or something that only existed in appearance, such as a dream. For example, we see the same Greek word used to describe something very real, the burning bush that appeared to Moses.
Acts 7:30-31 (ESV) - 30 Now when forty years had passed, an angel appeared to him in the wilderness of Mount Sinai, in a flame of fire in a bush. 31 When Moses saw it, he was amazed at the sight, and as he drew near to look, there came the voice of the Lord:
The word for vision is translated here as "sight" because it simply refers to the thing that was seen. If the burning bush is permitted to be a real event, then there is no reason that the mount of transfiguration cannot as well.
This event has the same character as Jesus' baptism.
Matthew 17:5 (ESV) - 5 He was still speaking when, behold, a bright cloud overshadowed them, and a voice from the cloud said, "This is my beloved Son, with whom I am well pleased; listen to him."
This event sounds very similar to another event: Jesus' baptism.
Matthew 3:16-17 (ESV) - 16 And when Jesus was baptized, immediately he went up from the water, and behold, the heavens were opened to him, and he saw the Spirit of God descending like a dove and coming to rest on him; 17 and behold, a voice from heaven said, "This is my beloved Son, with whom I am well pleased."
Certainly, Jesus' baptism and the Spirit of God was no figment of imagination. It was a real event that happened, just as the appearance of Moses and Elijah. The only reason why we would reject the idea that Moses and Elijah actually spoke with Jesus would be due to a pre-commitment to the INC's teaching apart from Scripture.
This passage points to the fact that Moses and Elijah were conscious, Moses continuing as conscious even beyond the grave. They spoke to Jesus in front of Peter, James, and John. The INC is restricted in their understanding of scripture, due to their theological bias and commitment to the false doctrine of soul sleep.
The INC therefore does not believe what Scripture itself teaches. INC members should repent of their unbelief and believe the true gospel.
 They argue for the resurrection of Moses from Jude 1:9 and ancient Jewish tradition.