Until we learn to pray without distractions and images, entering the closet and shutting the door as scripture has it (Matthew 6:6), we won't come to know Christ as He is, in His Divinity.
As for what it means to know Him in the flesh, St Maximus has a good explanation (imo):
The Logos of God is called flesh not only inasmuch as He became incarnate, but in another sense as well. When He is contemplated in His true simplicity, in His principial state with God the Father (cf. John 1:1-2), although He embraces the models of the truth of all things in a distinct and naked manner, He does not contain within Himself parables, symbols and stories needing allegorical interpretation. But when He draws near to men who cannot with the naked intellect come into contact with intelligible realities in their naked state, He selects things which are familiar to them, combining together various stories, symbols, parables and dark sayings; and in this way He becomes flesh. Thus at the first encounter our intellect comes into contact not with the naked Logos but with the incarnate Logos, that is, with various sayings and stories. The incarnate Logos, though Logos by nature, is flesh in appearance. Hence most people think they see flesh and not the Logos, although in fact He is the Logos. The intellect-that is, the inner meaning-of Scripture is other than what it seems to most people. For the Logos becomes flesh in each of the recorded sayings.
The initial stages of learning about religious devotion are naturally related to the flesh. For in our first encounter with religion we come into contact with the letter and not the spirit. But as we get nearer to the spirit and refine the materiality of words with the more subtle forms of contemplation, we come to dwell - so far as this is possible for man — purely in the pure Christ, so that we can say with St Paul, ‘Though we have known Christ according to the flesh, now we no longer know Him in this manner’ (2 Cor. 5:16). That is to say, we no longer know Him according to the flesh because, through the intellect’s naked encounter with the Logos stripped of the veils covering Him, we have advanced from knowing Him according to the flesh to knowing His ‘glory as of the only-begotten Son of the Father’ (John 1:14).