Greater than we can measure
When the Bible calls God great, it is not merely saying he is impressive. It means no one can be compared with him. David praises the Lord as worthy of the highest praise and says that God's greatness cannot be fully searched out (Psalm 145:3). We can know God truly, but we will never get to the end of who he is.
That is humbling. God is not simply a bigger version of us, with more strength and fewer problems. Job says that God's years cannot be numbered (Job 36:26). His life is not limited by time, and his being is not boxed in by the limits that shape every human life.
Great is the Lord, and greatly to be praised; and his greatness is unsearchable.
Great in power and wisdom
God's greatness appears in creation. Isaiah points to the stars and describes their Creator as the one whose strength ensures none of them is missing (Isaiah 40:25-26). The heavens may feel impossibly vast to us, but they are not beyond God's rule or attention.
His power is never reckless. Psalm 147 connects God's great power with understanding that cannot be counted or measured (Psalm 147:5). God does not need to guess what is happening or rush to find an answer. When your life feels confusing, God is not confused.
Great is our Lord, and of great power: his understanding is infinite.
Greatness and goodness belong together
Human greatness can look like status, force, or the ability to stand above others. God's greatness has a different character. When God revealed himself to Moses, he spoke of his mercy, grace, patience, faithfulness, forgiveness, and his justice toward evil (Exodus 34:6-7). His power and his goodness do not compete with each other.
This matters because power without goodness would be frightening. But David says the Lord is righteous in all his ways and holy in all his works (Psalm 145:17). God never uses his strength in a corrupt, selfish, or cruel way. His greatness is morally beautiful.
And the Lord passed by before him, and proclaimed, The Lord, The Lord God, merciful and gracious, longsuffering, and abundant in goodness and truth,
The great God sees people
God's greatness does not make ordinary people too small for him to notice. Looking at the heavens, David wondered why the Creator would give attention to humanity at all, yet he recognised that God does care for people (Psalm 8:3-4). Jesus spoke similarly, saying that the Father notices even sparrows and knows the details of his people's lives (Matthew 10:29-31).
So calling God great is not a vague religious compliment. It gives a reason to trust him, worship him, and pray honestly. You do not need to understand everything God is doing before bringing him what is in front of you. Read Psalm 145 slowly, and notice how David connects God's vast greatness with his kindness and care.