4. Titus, mine own son—Greek, "my genuine child" (1Ti 1:2), that is, converted by my instrumentality (1Co 4:17; Phm 10).
after the common faith—a genuine son in respect to (in virtue of) the faith common to all the people of God, comprising in a common brotherhood Gentiles as well as Jews, therefore embracing Titus a Gentile (2Pe 1:1; Jude 3).
Grace, mercy, and peace—"mercy" is omitted in some of the oldest manuscripts. But one of the best and oldest manuscripts supports it (compare Notes, see on 1Ti 1:2; 2Ti 1:2). There are many similarities of phrase in the Pastoral Epistles.
the Lord Jesus Christ—The oldest manuscripts read only "Christ Jesus."
our Saviour—found thus added to "Christ" only in Paul's Pastoral Epistles, and in 2Pe 1:1, 11; 2:20; 3:18.