12. suffer—rather, as the Greek is the same as in 2Ti 2:10, "If we endure (with Him)" (Ro 8:17).
reign with him—The peculiar privilege of the elect Church now suffering with Christ, then to reign with Him (see on 1Co 6:2). Reigning is something more than mere salvation (Ro 5:17; Re 3:21; 5:10; 20:4, 5).
deny—with the mouth. As "believe" with the heart follows, 2Ti 2:12. Compare the opposite, "confess with thy mouth" and "believe in thine heart" (Ro 10:9, 10).
he also will deny us—(Mt 10:33).