The brother, whose praise is in the Gospel - Who this brother was we cannot tell; some suppose it was St. Luke, who wrote a gospel, and who was the companion of St. Paul in several of his travels; others think it was Silas; others, Barnabas; others, Mark; and others, Apollos. Neither ancients nor moderns agree in either; but Luke, John, and Mark, seem to have the most probable opinions in their favor. Whoever the person was he was sufficiently known to the Corinthians, as we learn by what the apostle says of him in this place.

the brother. This is generally supposed to have been Said. Luke, 'whose praise was in all the churches,' on account of the gospel which he had written, and for many zealous services in its cause.

2 Corinthians 8:19,22,23 And not that only, but who was also chosen of the churches to travel with us with this grace...

2 Corinthians 12:18 I desired Titus, and with him I sent a brother. Did Titus make a gain of you? walked we not in the same spirit?...

throughout.

Romans 16:4 Who have for my life laid down their own necks: to whom not only I give thanks, but also all the churches of the Gentiles.

The Condescension of Christ
And now, dear friends, the argument of the apostle shall be our subject to-day. It divides itself in an extremely simple manner. We have first, the pristine condition of our Saviour--"He was rich." We have next, his condescension--"He became poor." And then we have the effect and result of his poverty--"That we might be made rich." We shall then close by giving you a doctrine, a question, and an exhortation. May God bless all these, and help us to tell them aright. I. First, then, our text tells …
Charles Haddon Spurgeon—Spurgeon's Sermons Volume 3: 1857

The Work of the Holy Spirit
The Church of Christ. "It is the Spirit that beareth witness, because the Spirit is ruth."--1 John v. 6. We now proceed to discuss the work of the Holy Spirit wrought in the Church of Christ. Altho the Son of God has had a Church in the earth from the beginning, yet the Scripture distinguishes between its manifestation before and after Christ. As the acorn, planted in the ground, exists, altho it passes through the two periods of germinating and rooting, and of growing upward and forming trunk and …
Abraham Kuyper—The Work of the Holy Spirit

Balak's Inquiries Relative to the Service of God, and Balaam's Answer, Briefly Considered.
"Wherewith shall I come before the Lord, and bow myself before the high God? Shall I come before him with burnt offerings, with calves of a year old? Will the Lord be pleased with, thousands of rams, or with ten thousands of rivers of oil? Shall I give my first born for my transgression; the fruit of my body for the sin of my soul?--He hath shewed thee, 0 man, what is good: And what doth the Lord require of thee, but to do justly, and to love mercy, and to walk humbly with thy God?" As mankind are …
Andrew Lee et al—Sermons on Various Important Subjects