Notes on Ephesians (from “The Annotated Bible” volume 3): 

The central verse in the first three chapters of Ephesians is found in chapter 2:10.  ^“For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them” (NASB).The word, “workmanship” is in the Greek, “Poima,” from which our word “Poem” is derived.  It is a beautiful thought in itself to think of those who are saved by grace, and united to Christ as “the poem of God."  But the word "Poiema” may also be rendered “Masterpiece” or “Masterwork." 

Only once more is the same word found in the original language of the New Testament Scriptures.  In Romans 1:20 it is used in connection with the physical creation.  God has produced two great masterworks in which He manifests His power.  He called the universe into existance out of nothing.  What He, as the Omnipotent One can do, is seen in the creation of the heavens and the earth and in the sustenance of His creation.  His eternal power and Godhead are revealed in creation (Romans 1:19-20).  But the creation of the universe out of nothing is not the greatest masterpiece of God.  God has done something greater.  He has produced a work which reveals Him in a far higher degree.  That greater masterpiece is the redemption of sinners.   

God took only six days to bring order out of the chaos of the disturbed original creation and to call into existence the present eath and heavens.  But He spent forty days with Moses in directing him to build the tablenacle, because the work of redemption is more glorious than the work of creation.

Gaebelein, A. C. (1970). Volume 3. In The annotated Bible; the Holy Scriptures analyzed and annotated. [Neptune, N.J.]: Moody Press, Loizeaux Bros.