'Messenger' in the Bible

Paul, an apostle (special messenger, personally chosen representative) of Christ Jesus (the Messiah) by the will of God, and Timothy our brother,To the church of God which is at Corinth, and to all the saints (God’s people) throughout Achaia (southern Greece):

Because of the surpassing greatness and extraordinary nature of the revelations [which I received from God], for this reason, to keep me from thinking of myself as important, a thorn in the flesh was given to me, a messenger of Satan, to torment and harass me—to keep me from exalting myself!