The idea that the Lord Jesus existed in heaven and came to earth by way of Mary's womb is an amazing idea. Some believe that the Son of God appeared to mankind several times before he was born of the virgin. Many believe that he appeared to men as "the Angel of the Lord". Consider how Jacob is said to have wrestled with God or that Moses saw the Angel of the Lord in the burning bush. Jesus life before becoming human is a divine mystery.
So when Christ speaks of coming from, and returning to, the Father he gives us a glimpse of what he meant when he spoke of knowing Abraham. It is hard to imagine how much Jesus suffered on earth. Unlike heaven, on earth he was confined by the limitations of time and space. The relationship with the Father was so much different on earth. Considering this helps me to understand better his sacrifice and suffering for our salvation.
Thank you Lord for giving up heaven that I might gain heaven.