They mean: everything you will wish to know about me, Tychicus will tell you all of it. To assign one special subject to "the things concerning me" and another to "what I am doing" is unnecessary concern. It can give nothing positively certain except an increase of words. The Apostle does not describe in detail who Tychicus is, either here or in other epistles. In Acts it is said that he was an Asian by birth (Acts 20:4), from the region where Ephesus was and where the Apostle labored so long in the Gospel. It is easy to infer that he was a believer sincerely attached to the Apostle. He was chosen by him to assist the Gospel in whatever way he could. It is evident that he carried epistles. But since much was entrusted to him to supplement them, one must suppose that he had the mind and character fitting him to fulfill faithfully such an important commission. The Apostle indicates these qualities in him when he calls him a beloved brother. That is, he is a Christian worthy of every love by mind and character, and loved by me. This is a high recommendation. But the following one is still higher: "a faithful minister in the Lord." Minister does not mean servant, but diakonos, the one who carries out entrusted commissions or one entrusted task, like the seven deacons in the Church of Jerusalem. By this St. Paul wished to indicate: my helper and fellow laborer in the work of the Gospel. "Faithful." As I rely on him in everything, so you who already know him may do also. He is faithful, and therefore he will tell you the whole truth, as everything is. And if you have need to communicate anything through him, you may rely on him completely. "In the Lord." He is faithful, and he takes upon himself the labors of service to the Gospel not from human motives, but in the Lord. He acts in the fear of God, before the face of the Lord, for His glory and for the glory of His holy Gospel, without any calculations.