Concerning the motive for the creation in the mind of God, the Orthodox Confession and the Longer Orthodox Catechism express it thus: The world was created by God “so that other beings glorifying Him, might be participants of His goodness.”
The idea of the mercy and goodness of God, as expressed in the creation of the world, is to be found in many Psalms, such as Psalms 102 and 103 (“Bless the Lord, O my soul”), which call on one to glorify the Lord and give thanks for one's existence and for all of God's providence.
The same thoughts are expressed by the Fathers of the Church. Blessed Theodoret writes, “The Lord God has no need of anyone to praise Him; but by His goodness alone He granted existence to angels, archangels, and the whole creation.” Further, “God has need of nothing; but He, being an abyss of goodness, deigned to give existence to things which did not exist.” St. John Damascene says (as we have just seen), “The good and transcendentally good God was not content to contemplate Himself, but by a superabundance of goodness saw fit that there should be some things to benefit by and participate in His goodness.”
Read it here.