Not now as a servant, but above a servant, a brother beloved, specially to me, but how much more unto thee, both in the flesh, and in the Lord? No longer a mere slave (though still that), but above a servant, so that thou shalt have not merely the services of a slave, but higher benefits: a servant "in the flesh," he is a brother "in the Lord." Beloved, specially to me - his spiritual father (Philemon 1:10); who have experienced his faithful attentions. Lest Philemon should dislike Onesimus being called "brother," Paul first recognizes him as a brother, being the spiritual son of the same God.
Much more unto thee - to whom he stands in so much nearer and more lasting relation.