Paul begins Ephesians by telling them he was "an apostle of Christ Jesus by the will of God" (Eph 1:1). He told the Colossians "of this church I was made a minister according to the stewardship from God bestowed on me for your benefit, so that I might fully carry out the preaching of the word of God" (Col 1:25). According to the Greek word diakonos for minister Paul was a servant. To be preaching meant that he was proclaiming the gospel. Jesus told Ananias, "'Go, for he is a chosen instrument of Mine, to bear My name before the Gentiles and kings and the sons of Israel'" (Ac 9:15). Christ also "humbled Himself by becoming obedient to the point of death" (Php 2:8) and became "a servant to the curcumcision on behalf of the truth of God to confirm the promises given to the fathers" (Ro 15:8). However, Jesus was also prophetically "the Preacher, the son of David, king in Jerusalem" (Eccl 1:1). "The Preacher also taught the people knowledge" (12:9). Jesus was "called Rabbi by men" (Mt 23:7) "which translated means Teacher" (Jn 1:38).
Paul said "I was appointed a preacher and an apostle and a teacher" (2Ti 1:11). It was in accordance with "the hope of the gospel . . . of which I, Paul, was made a minister" (Col 1:23) and according to the "promise of Christ Jesus through the gospel, of which I was made a minister" (Eph 3:6-7). However it was by "the gift of God's grace which was given to me according to the working of His power" (:7) in that "this grace was given to preach to the Gentiles" (:8). He told the Galatians that God "had set me apart even from my mother's womb [and] called me through His grace, [and] was pleased to reveal His Son in me so that I might preach Him among the Gentiles" (Gal 1:15-16). Then he continues saying, "the gospel which was preached by me is not according to man . . . nor was [I] taught it, but received it through a revelation of Jesus Christ" (:11-12). This is when he "went away to Arabia" (:18) ["Mount Sinal [is] in Arabia" (4:25)] and after staying in "Damascus . . . three years later I went up to Jerusalem" (:17-18). The original twelve apostles had also been with Jesus for three years.
Paul reminded the Ephesians that "you have heard of the stewardship of God's grace which was given me for you; that by revelation there was made known to me the mystery" (Eph 3:2). It is a mystery because it had never been revealed. "We speak God's wisdom in a mystery, the hidden wisdom which God predestined before the ages through our glory" (1Co 2:7). But when you read Paul's doctrine it isn't necessarily easy to understand because even Peter said "in all his letters, speaking in them of these things . . . [there] are some things hard to understand" (2Pe 3:16). Its as if you need a revelation to understand the revelation. Doctrine can be just words, plus "a natural man does not accept the things of the Spirit of God . . . because they are spiritually appraised (1Co 2:14). Fortunately "we have received . . . the Spirit who is from God, that we might know the things freely given to us by God" (:12). Paul prayed "that the eyes of your heart may be enlightened, so that you will know what is the hope of His calling" (Eph 1:18). Furthermore, he prayed "that the God of our Lord Jesus Christ, the Father of glory, may give you a spirit of wisdom and of revelation in the knowledge of Him" (:17). He also provides hope citing "by referring to this, when you read you can understand my insight into the mystery of Christ" (3:4). It comes by "Him who is able to establish you . . . according to the revelation of the mystery which has been kept secret for long ages past" (Ro 16:25). We are "attaining to all the wealth that comes from the full assurance of understanding, resulting in a true knowledge of God's mystery, that is Christ Himself, in whom are hidden all the treasures of wisdom and knowledge" (Col 2:2-3).