Other than God’s deserving our praise, does Augustine offer any motivations to praise God?
Those who praise you, O Lord, speak of the excellence of your terrible deeds, the greatness of the work of your hands which punish and distribute discipline. They shall speak and will not remain silent…For it is the praise of God that sets you on your way that ought to show you both what you should love and what you should fear… Let the excellence of your terrible things be proclaimed now. Although it is endless, so, too, your greatness has no end, and they shall not be silent about of it. How shall they tell of it if it has no end? They shall proclaim it with their praise; and because there is no end of it, so, too, there will be no end to his praise.
from St. Augustine Answers 101 Questions on Prayer by Fr. Ermatinger
God deserves our praise; this is a moral absolute and a moral obligation. This is man’s sacred duty. That God is God is enough to necessitate and enough to compel both as the reward of praising, which is to praise, and punishment for not, which is to be denied the ability to praise. Now it may seem that praising might be of little reward until it is realized that the praising of God is the purpose of man and in achieving that end, there is corresponding joy. Yet God has made man not just for praising but He has made man for Himself – if God should give man Himself, and man should see God as He is, face to Face with no mediation, the praise that man will offer will be eternal and the joy that man shall have shall be likewise eternal. No small thing for simply doing man’s religious obligation. Yet again God calls man not simply to fulfill obligations but beyond obligations and their limited rewards to participation and thus merit. Man’s praise becomes something more, for God’s will becomes manifest in creation through man’s cooperation in it. By grace, man’s will aligns itself perfectly with God’s will and, by grace, man accomplishes what God wills. This is not obligation stemming from nature, nor a slave fulfilling a master’s commands, but it is the alignment of lover and beloved. Grace crowns grace, the action is meritorious, and the praise owed to God stems from the fullness of the union between God and man. To this praise is owed the meritorious receiving of God which, in turn, brings forth more praise… and so on into eternity. There shall be no end to the praise offered to God for there is no end to God and the fullness of God received in Mystical Marriage is a spring ever welling up in the heart of the beloved’s soul.
Consider the excellence of God’s terrible things, those things that He gives to those whom He must discipline and those to whom He must punish for their obstinate refusal to praise Him. These things are called terrible not because they are evil, for God is not the author of evil, but because they are, in fact, good. They are goods that are applied to the disobedient but not received by them. God permits man to choose not to praise him, but this is for a time, for man’s end is to praise God and praise Him he shall, but not by his will. The disobedient will praise God by the justice applied to them, and, more so, by the mercy applied to them. Consider the terrible justice of God that those who will to disobey Him shall be forced to acknowledge Him as Lord and the justness of their punishment, and to never again act contrary to His will. For those that will to only disobey, this is tantamount to not acting at all; to being bound in chains of iron and cast into outer darkness. Consider the terrible mercy of God that those who will to not praise Him that, by His mercy, they shall achieve their end and praise Him, not by their will but by the existence of their being. For those who wished to exist without God, which is to not exist, shall be denied that by God’s mercy. They shall receive that which they do not want, hate it all the more, but only praise Him in their wailing and gnashing of teeth, the sweet name of the Merciful God being akin to molten brass upon their lips.
What then of the blessed who shall look upon those that have rejected God and have received His terrible things? Should this not be a cause of praising God, and not of sorrow? If God’s terrible things should have an end, there should not be praise for Him. If there is an end, justice will be incomplete, and mercy not given. Ultimately, God would not be good and there would be no sense in praising Him if there should be an end to His mercy or His Justice, if man, whom He has created, should not achieve his end, man’s will to not praise God should triumph, and God should be faithless to His promises. The terrible things of God shall not be cause of sorrow, but praise, and because God’s mercy and justice will not end the praise shall be without end.