The Greek word apodeiknumi

Found just four times in the New Testament (Acts 2:22; 25:7; 1 Cor. 4:9; 2 Thess. 2:4), the Greek verb “apodeiknumi” meant “prove,” “proclaim,” “set forth,” “display.”

In Acts 2:22 and Acts 25:7 this verb means “to prove” (miracles proved Jesus to be associated with God and charges could not be proven against the apostle Paul).  In the other two references a good definition is “set forth.”  Paul felt as if he was set forth as a spectacle (1 Cor. 4:9), and the “man of sin” is described as being “set forth” as God in 2 Thess. 2:4.