Matt. 5:1 "And when He saw the crowds, He went up to the mountain. And after He sat down, His disciples came to Him."
Matt. 17:1 "And after six days Jesus took with Him Peter and James and John his brother, and brought them up to an high mountain privately."
Matt. 24:3 "And as He sat on the Mount of Olives, the disciples came to Him privately, saying, Tell us, When will these things be? And what will be the sign of Your coming and of the consummation of the age?"
Matt. 28:16 "And the eleven disciples went to Galilee, to the mountain where Jesus directed them."
On the mountain Jesus revealed major truths. If you were a casual follower and never climbed the mountain with Him for these special events, you missed whole vistas of revelation. You missed major opportunities to hear something or experience something that would redirect the course of your life.
This is the sort of thing that happens at Christian conferences. And this apparently wasn't lost on the Lord. He purposely got away from the hustle and bustle of teh daily grind with its incessant demands and distractions. This not business as usual.
Of the thousands of people Jesus interacted with during His ministry, only 120 were there in the upper room on the day of Pentecost. Most likely the people that carried on His move had climbed the mountain with Him before.
Peter referring to his experience on the mount of transfiguration, says that he became an "eyewitness of that One's majesty" (2 Peter 1:16). Yes, you can always get the audio later, see the pictures on Facebook, and catch all the best quotes on Twitter, but you won't feel the direct impact of being an eyewitness. There's something about being there that changes you.
Only an eyewitness was a suitable replacement for Judas in the circle of the twelve (Acts 1:21,22).
Attending Christian conferences gives the Lord an opportunity to do something special in your life, appear to you in an unprecedented way, and call you into direct participation in His eternal economy.