1: ποιέω
(Strong's #4160 — Verb — poieo — poy-eh'-o )

"to do, to make," is thrice rendered "execute," of the Lord's authority and acts in "executing" judgment, (a) of His authority as the One to whom judgment is committed, John 5:27; (b) of the judgment which He will mete out to all transgressors at His Second Advent, Jude 1:15; (c) of the carrying out of His Word (not "work," as in the AV) in the earth, especially regarding the nation of Israel, the mass being rejected, the remnant saved, Romans 9:28 . That He will "execute His Word finishing and cutting it short," is expressive of the summary and decisive character of His action. See DO.

2: ἱερατεύω
(Strong's #2407 — Verb — hierateuo — hee-er-at-yoo'-o )

"to be a priest, to officiate as such," is translated "executed the priest's office," in Luke 1:8 . It occurs frequently in the Sept., and in inscriptions. Cp. hierateuma, "priesthood," 1—Peter 2:5,9; hierateia, "a priest's office," Luke 1:9; Hebrews 7:5; hiereus, "a priest," and hieros, "sacred."