Soli Deo Gloria!
Soli deo gloria, which means glory to God alone! The meaning of “To God be the glory?” God is the Supreme Being and Creator of all. To glorify Him means that we are to acknowledge the greatness and splendor of His Majesty through honor, worship and praise of which He alone is worthy because He is God of all.
Praise to God does not have any exaggeration. Every praise to God is an absolute truth. It is said that any praise to God is a statement of reality even though it looks like a praise. Praise is the result of exalting His name. To God alone is are the praises we give to Him.
Since every praise of God is truth without any trace of exaggeration, there is no fault at all in praising God. When you praise yourself or other human beings, sin results due to total or partial lie existing in it. In the praise of God, since there is no lie and hence there is no sin, there is no place of criticism of such statement of truth from anybody. Knowledge of truth is the meaning of the word ‘Veda’. Soli deo gloria!
God the author of the Veda has given the knowledge of absolute truth without any trace of lie or exaggeration in it. Communication of truth to the humanity is the basic idea of God. If a human being has written a prayer on himself, which generally consists of total or partial lie, the objection posed by you may have some value. Even in the case of human beings, it is not necessary that every human being writes praise of himself consisting total or partial exaggeration.
He may write a statement of truth about himself without any exaggeration. If somebody writes that he is born in 1947, there is no exaggeration or praise in it. In the case of God, the case is totally different. Any extent of praise stated by God or stated by devotees is only absolute naked truth without even a trace of lie. Therefore, no statement of God about Himself or no statement of God by any devotee can be criticized in any context.
Encourage Yourself: There is nothing which God cannot do (omnipotence) and nothing which God cannot know (omniscience). Therefore, God is beyond the criticism of any created soul. The Gita says that one just knows the factual concepts of God from all the Vedas.