In his book The End for Which God Created the World (printed in God’s Passion for His Glory by John Piper) Jonathan Edwards describes what God’s glory is in Himself and what it is when manifested to us. This is how Edwards describes God’s glory within Himself:
The whole of God’s internal good or glory, is in these three things, his infinite knowledge, his infinite virtue [love] or holiness, and his infinite joy and happiness (p. 244).
God communicates (emanates) His internal glory to us by communicating His knowledge of Himself, His love of Himself, and His happiness in Himself. Therefore, we glorify God by knowing, loving, and rejoicing in God’s glory as God knows, loves, and rejoices in Himself.
And in these things, knowing God’s excellency, loving God for it, and rejoicing in it, and in the exercise and expression of these, consists God’s honor and praise; so that these are clearly implied in that glory of God, which consists in the emanation of his internal glory (p. 245).
Thus God’s glory is reflected in us. As God’s internal glory is in His mind (knowledge) and will (love, joy), so He manifests His external glory to our minds and wills.
God communicates himself to the understanding of the creature, in giving him the knowledge of his glory; and to the will of the creature, in giving him holiness, consisting primarily in the love of God: and in giving the creature happiness, chiefly consisting in joy in God. These are the sum of that emanation of divine fullness called in Scripture, the glory of God. The first part of this glory is called truth, the latter, grace, John 1:14. “We beheld his glory, the glory of the only-begotted of the Father, full of grace and truth.” (pp. 246-246)
These three things – knowing, loving, and rejoicing – are found in 1 Peter 1:8 in reference to believers toward Christ:
Though you have not seen him, you love him. Though you do not now see him, you believe in him and rejoice with joy that is inexpressible and filled with glory (ESV).
Is this none other than a believer “seeing” the glory of Christ in the gospel and coming to know, love and rejoice in Him?
One final observation: Edwards indicates that God’s love for Himself manifests itself in holiness and happiness. And so our response to God’s glory should be a love for God that expresses itself in holiness and happiness. Thus holiness is driven by love for God and happiness in God is love overflowing in joy.