Charles Spurgeon Commentary 2 Corinthians 8:17-18

"For he accepted indeed our exhortation; but being himself very earnest, he went forth unto you of his own accord. And we have sent together with him the brother whose praise in the gospel [is spread] through all the churches;" — 2 Corinthians 8:17-18 (ASV)

For indeed he accepted the exhortation; but being more forward, of his own accord he went unto you. And we have sent with him the brother, whose praise is in the gospel throughout all the churches;

I do not know who "the brother" was. There have been many guesses, but perhaps none of them were right. You see that human praise, even in the church, is not a very lasting thing. There was somebody whom all Christians praised; yet, now, nobody knows him. So, if you become esteemed among men, you may be unknown, even as this good man is; but if you have the praise of God, he will never forget you.