In biblical teaching summarized by Reformed theology, the creator-creature distinction brings into view the absolute ontological difference between the Triune God and the creature. The Triune God is infinite, eternal, and unchangeable in His being wisdom, power, holiness, justice, goodness and truth.
And the creature that comes into existence by an act of God’s sovereign will is not eternal, but temporal, not infinite, but finite, not immutable, but mutable. And the distinction between the two remains in the Creator-creature relation. While God is infinite, eternal, and unchangeable apart from His relation to the creature, He remains such in relation to the creature.
If you narrow it down to the doctrine of Adam’s special creation as the image of God, the Creator-creature distinction is summarized so beautifully Westminster Confession 7.1. Though God is infinitely transcendent over the creature, He nonetheless condescended to the image-bearing creature and offered Himself to the creature as the creature’s blessedness and reward. Adam’s reward in relation to God under covenant was God himself. God is his blessedness and reward.
The creator-creature distinction and relation drives you to remember that the final, eternal and unchangeable Triune God is not only the transcendent sovereign over the creature but the one who in creation and in the voluntary condescension of covenant offered Himself to Adam for His blessedness and reward. And after the fall, he comes to be the blessedness and reward of every creature who is redeemed by Jesus Christ as the Last Adam. So that in union with Jesus Christ as the Last Adam the Triune God is the blessedness and reward of the church.