I read this the other day and it has stuck in my mind:

Glory is virtually the physical manifestation of all the perfections of God’s being — His goodness, truth, faithfulness, righteousness, holiness and wisdom. (Sinclair Ferguson, In Christ Alone p59.)

If I hold this concept in mind, then consider that even the seraphim who dwell in God’s presence cannot look directly upon His glory but cover their eyes (Isaiah 6:2) and that He dwells in unapproachable light (1 Timothy 6:16), I begin to appreciate the awesome perfection of God.

When Moses asked to see God’s glory, God told him that He would make His goodness pass by him (Exodus 33:18-19). After this encounter the face of Moses shone and even his brother was afraid to go near him (Exodus 34:29-30). Being in the presence of the perfect One had changed Moses so that his own being now radiated or reflected glory.

All of us who love Christ probably long to be in His presence as Moses was, yet I am also greatly afraid to be so immediately in God’s presence. Isaiah knew the fear of encountering God and I know my sinful heart well enough to know that I also would be completely undone in that situation (Isaiah 6:5).

Then, having been blown away by the glory of the perfection of God, I come to the command of Jesus in  Matthew 5:48, “You therefore must be perfect, as your heavenly Father is perfect.” This is a hard call for us sinful humans, but I can explain no better than the ESV Study Bible notes for this verse:

Scripture is a reflection of God himself as he has made his will and character known to his people. As Christians seek to live in conformity to Scripture, they are in fact pursuing the very perfection of God.