Psalm 69:30 I will praise the name of God with a song, And will magnify Him with thanksgiving.
How can we even think we can make God great? The answer is, of course we cannot make Him great because He is already greater than anything.
What we can do, though, is to lift up our praises and worship of Him so others can see just how awesome and great He is.
Being open and honest about our feelings toward God will go a lot further than our descriptions of Him too; how do we describe the indescribable?