Christ speaks of the perfect happiness of believers, as if he had said, that his desire will not be satisfied till they have been recieved into heaven. In the same manner I explain the beholding of the glory. At that time they saw the glory of Christ, just as a man shut up in the dark obtains, through small chinks, a feeble and glimmering light. Christ now wishes that they shall make such progress as to enjoy the full brightness of heaven. In short, he asks that the Father will conduct them, by uninterrupted progress, to the full vision of his glory.As Calvin says, the perfect happiness of believers is found in beholding the glory of Christ. This is what Jesus is saying in John 17:24. Therefore, as Christians, should this not leave us with an all-consuming longing to see more of Christ in this life, as He is revealed to us in Scripture, and ultimately to see the fullness of His glory in the new creation. Should this not leave us with a longing for Him either to call us to depart to be with Him - which is better by far (Philippians 1:23), or to return to ussher in the new creation, where we shall see Him face to face (Revelation 21:22-23; 22:4).