Clement quotes Clement of Rome as an Apostle

Moreover, in the Epistle to the Corinthians, the Apostle Clement also, drawing a picture of the Gnostic, says: “For who that has sojourned among you has not proved your perfect and firm faith? and has not admired your sound and gentle piety? and has not celebrated the munificent style of your hospitality? and has not felicitated your complete and sure knowledge? For ye did all things impartially, and walked in the ordinances of God;” and so forth.

Clement of Alexandria
The Stromata, Book IV
Chapter XVII

Early admonitions against racism

And it prohibits an ox and ass to be yoked in the plough together; pointing perhaps to the want of agreement in the case of the animals; and at the same time teaching not to wrong any one belonging to another race, and bring him under the yoke, when there is no other cause to allege than difference of race, which is no cause at all, being neither wickedness nor the effect of wickedness.

Clement of Alexandria
The Stromata, Book II
Chapter XVIII