When Christ walked the earth He looked normal, like any other person, but on the Mount of Transfiguration His face became so bright it shone like the sun. (Mt 17:1-2) This is evidently His natural state, what He’s like when He isn’t veiled, disguised, subdued.
For example, when Jesus appears to Paul from Heaven His face is even brighter than the sun. (Ac 26:13) And we find the same when Jesus appears to John years later (Re 1:16); Christ is so overwhelming in His mere appearance our dear brother John faints dead away. (17a)
Further, when Christ returns to reign on Earth, His very brightness destroys His enemies. (2Th 2:8) So, He’s already toning it down a good bit when He appears to the apostles and to Paul.
Jesus is the brightness of God (He 1:1-3); He Who made the universe outshines all the stars together. (Co 1:16) When Jesus walks into a room, unless He gets out His dimmer switch and tones it down, we will not only be unable to look at Him — any more than we can stare directly into the sun — in our natural state we’ll need to take cover and/or shield ourselves from His brightness in order to survive… if anything actually could shield us from it. And this is when He’s in a kind, loving, gentle mood.
What then will it be like when He’s angry? When Jesus Christ, the Lord of glory, rises up from His eternal throne in a full on, indignant rage? (Je 10:10) At the end of the age, when the King of Kings shows up in all His glory and splendor (Re 19:16), full of wrath and fury (2Co 5:11) we have no idea what that will be like – nothing in all Creation can endure His undiluted, unfiltered, angry presence (Re 6:16-17): Creation itself will try desperately to flee and find no cover. (Re 20:11)
When He came the first time, Jesus Christ of Nazareth was unimpressive, not much to look at. (Is 53:2b) Born in a stable among some animals, to a poor family from a very poor community, having no formal education, He essentially came to us incognito. If He hadn’t veiled His glory like this His enemies wouldn’t have been able to act like enemies; He was pleased to give them the opportunity to express their nature before the universe, which they certainly did, for all of us to ponder. (1Th 2:16)
And I suppose it’s reasonable to expect this is why He still seems to be mostly in hiding, not typically showing Himself in unmistakable, overwhelming ways just yet (He 12:18-21): it’s evidently to let us all show who and what we are before He throws open the doors of the Heavenly Courtroom. (Ro 9:22) He will do so, some day. (Ro 2:4-6)
So, it’s wisdom to kiss the Son lest He be angry, and we perish from the way, when His wrath is kindled just a little. (Ps 2:2) Let’s not trifle with Jesus (2Co 5:11); He’s been incredibly kind and merciful to deliver us from the wrath to come (1Th 1:10), but let’s not disrespect Him or take Him for granted; He’s to be feared as well as loved. So, let’s honor and revere Him as He deserves (Jn 5:23), serving and obeying Him with fear and trembling. (Php 2:12)