In the letter itself the designation of the writer and of those addressed first claims our attention. The writer identifies himself as "Paul, an Apostle of Jesus Christ by call, through the will of God." An Apostle is one sent, as Christ was sent by the Father. "As the Father sent Me, even so send I you." It was therefore an office no one could take to himself, nor was it the promotion resulting from previous service. To the apostleship the sole entrance was through the call of Christ; and in virtue of this call Paul became, as he says, an Apostle. And it is this which explains one of the most prominent of his characteristics: the singular combination of humility and authority, of self-depreciation and self-assertion. He is filled with a sense of his own unworthiness; he is "less than the least of the Apostles," "not worthy to be called an Apostle." On the other hand, he never hesitates to command the Churches, to rebuke the foremost man in the Church, to assert his claim to be listened to as the ambassador of Christ. This extraordinary humility and equally remarkable boldness and authority had one common root in his perception that it was through Christ's call and by God's will he was an Apostle. The work of going to all the busiest parts of the world and proclaiming Christ was to his mind far too great a work for him to aspire to at his own instance. He could never have aspired to such a position as this gave him. But God called him to it; and, with this authority at his back, he feared nothing, neither hardship nor defeat. And this is for us all the true and eternal source of humility and confidence. Let a man feel sure that he is called of God to do what he is doing, let him be fully persuaded in his own mind that the course he follows is God's will for him, and he will press on undauntedly, even though opposed. It is altogether a new strength with which a man is inspired when he is made conscious that God calls him to do this or that, when behind conscience or the plain requirements of human affairs and circumstances the presence of the living God makes itself felt. Well may we exclaim, with one who had to stand alone and follow a solitary path, conscious only of God's approval, and sustained by that consciousness against the disapproval of all, "Oh that we could take that simple view of things as to feel that the one thing which lies before us is to please God! What gain is it to please the world, to please the great, nay even to please those whom we love, compared with this? What gain is it to be applauded, admired, courted, followed, compared with this one aim of not being disobedient to a heavenly vision?"