I think Moses and Elijah is the strongest proof that we have in scripture for someone being alive after the physical body has died in Moses' case.
No it's not proof at all. Where in this scripture does it say Abraham's bosom.
THE TRANSFIGURATION - Matt 17:1-13
This scripture is a vision of what is to come.
It's describing the rapture and the first resurrection.
A vision is described as (that which will or may come to be), (anticipation)..
vi·sion - noun
1. the act or power of sensing with the eyes; sight.
2. the act or power of anticipating that which will or may come to be: prophetic vision; the vision of an entrepreneur.
3. an experience in which a personage, thing, or event appears vividly or credibly to the mind, although not actually present, often under the influence of a divine or other agency: a heavenly messenger appearing in a vision. Compare hallucination ( def 1 ) .
4. something seen or otherwise perceived during such an experience: The vision revealed its message.
5. a vivid, imaginative conception or anticipation: visions of wealth and glory.
Transfiguration and transformation both come from the Greek verb metamorphoo, meaning “to change into another form.”
While the transfiguration doesn’t directly give us information on the state of the dead, it retains theological significance nonetheless. When Peter recounted his experience in 2 Peter 1:16–18, he writes that he witnessed Christ’s coming at that time. In other words, he understood the experience to represent the return of Jesus Christ. Moses and Elijah represent the two classes of God’s people who will be present at that miraculous event: Moses represents the “dead in Christ” who rise to new life, and Elijah represents “those who are alive and remain” who will be translated to heaven and eternal life without ever experiencing death in the first place (1 Thessalonians 4:16). Understanding that the transfiguration is a representation of the second coming of Christ also helps us understand Christ’s promise that “some standing here … shall not taste death till they see the kingdom of God,” spoken a few days before the transfiguration (Luke 9:27).
When we understand the profound significance of this event in light of what Moses and Elijah represent, we can gain an understanding of the nature of death as a result. There would be no need of a bodily resurrection if everyone immediately went to heaven to live in Christ’s presence at death; similarly, translation to heaven would have no special significance because everyone would go to heaven immediately upon death. Moses and Elijah act as evidence that death brings a sleep of unconsciousness while the sleeping saints await the return of Jesus Christ.
Moses upon the mount of transfiguration was a witness to Christ’s victory over sin and death. He represented those who shall come forth from the grave at the resurrection of the just. Elijah, who had been translated to heaven without seeing death, represented those who will be living upon the earth at Christ’s second coming, and who will be “changed—in a moment, in the twinkling of an eye, at the last trumpet;” when “this mortal must put on immortality,” and “this corruptible must put on incorruption.” 1 Corinthians 15:51-53. Jesus was clothed with the light of heaven, as He will appear when He shall come “the second time without sin unto salvation.” For He will come “in the glory of His Father with the holy angels.” Hebrews 9:28, KJV; Mark 8:38. The Saviour’s promise to the disciples was now fulfilled. Upon the mount the future kingdom of glory was represented in miniature—Christ the King, Moses a representative of the risen saints, and Elijah of the translated ones.
