John 6:46. 'Not that any man hath seen the Father, save he which is of God, he hath seen the Father.'
This passage makes me think that only Spirit can see Spirit. Man, with his eyes, cannot see God.
The angel of the LORD appears on a number of occasions [Genesis 22; Exodus 3; Numbers 22; Judges 6; Judges 13; 2 Kings 1 etc.]. I'm a bit reluctant to say that they saw Jesus because I link the name Jesus with the baby born to Mary. I believe, in the cases above, the Spirit of the Father, the Word, came to earth in the form of an angel. What men saw was an angel, speaking and acting with the authority of God. This was the same Spirit, or Word, that brought about Mary's conception, and later anointed Jesus.
Since men cannot see God, God must take a form of some kind in which to make Himself known. At the time of the Exodus from Egypt, God chose to appear in cloud and fire etc. Only in His coming as the Suffering Servant does he appear in flesh and blood. At his coming in glory, I think he'll be recognisable whilst also being incorruptible and spiritual.
Do you think I'm mistaken?