There are a lot of really cool places on earth that the grand majority of us will never be permitted to go. I'm not talking about the prohibitive costs of taking a vacation to New Zealand or anything like that. I'm talking about places like Area 51 or the Presidential Emergency Operations Center under the East Wing of the White House. We just don't have the clearance to go into places like that. They're places like the old Forbidden City of the Chinese Emperor; there's a very small list of people who are privileged to have access to the wonders inside. One of the grandest of such places was the portable tabernacle that served as Israel's temple during their wilderness wanderings. I can't imagine that most Israelites wouldn't have been itching to take a look inside that place! They had given so much jewelery and costly fabrics that went into the construction of the thing; they knew it had to be palatial on the inside, but only one family was permitted to go inside, and then only one man out of that family was privileged to enter into the Most Holy Place, and that only once a year.
Another one of those places that we wish we could have been at as we read the Old Testament is in that cleft of the rock when Moses got to see the glorious back of God as He passed by. But again, that's one of those places that had an extremely short guest list: one person! If we don't have a good understanding of the concept of grace, then this exclusivity can seem unfair. "Why does he get to see the glory of God like that and the rest of us just have to take it on faith!?"
Fascinatingly, though, God does something wondrous in those who have the special blessing of drawing so near to Him: He makes them living pictures to the rest of the people of the glory that they had the privilege to experience.
When you look at the pattern of the priestly garments in Exodus 28, what you find is that they are made of the same kind of stuff as the tabernacle: blue, purple, and scarlet yarn, fine twined linen, and gold. In fact, the really intriguing thing about the outfit that the High Priest wears is that it just like the Most Holy Place, only inside-out! The tabernacle was veiled all around by a courtyard-fence of white linen (this is a picture of the Glory-Cloud, by the way), but what was outside for the tabernacle was inside for the High Priest: he wore the white linen as underwear (Exodus 28:42). Next came the blue, purple and scarlet cloth (the colors of fire - the heart of the Glory-Cloud). These colors made up the interior of the tabernacle, and they were clearly visible as the main outer garments of the High Priest. Finally, at the center of the Holy of Holies, and as the outermost layer of the priestly garments, there is gold (the glory of the presence of the Lord enthroned in the Glory-Cloud). The High Priest was the only one permitted to go into the glorious Most Holy Place of the tabernacle, but when he came out, all the rest of the Israelites had but to look at him to get an idea of what the inside was like - he was wearing it!
The same was true of Moses being allowed to see the glory of the Lord in the cleft of the rock (Exodus 33:18-33). He had the great privilege of seeing this most glorious of all sights, but then as he came down the mountain, his own face was shining like the sun (Exodus 34:29-30). Just as with the High Priest, he was the witness to the rest of the people of the glory of the presence of God.
Very significantly, believers in the New Covenant have this same ministry. "For God, who said, 'Let light shine out of darkness,' has shone in our hearts to give the light of the knowledge of the glory of God in the face of Jesus Christ." (2 Corinthians 4:6) We are then to take our vision of this glory that we have received and "shine like lights in the world" (Philippians 2:15) and "let your light shine before others" (Matthew 5:16). The unbelievers are outside the tent entirely, but we as believers have entered in beyond the veil (Hebrews 10:19-20) into the Most Holy Place in Christ. Therefore, we are witnesses, so wear the holiness of Christ and the testimony of His glorious gospel where all can see it, and thus introduce others to this awesome God that has graciously allowed us to see His majesty.