Jamieson, Fausset and Brown on 1 Corinthians 13:2

2. mysteries--(Ro 11:25; 16:25). Mysteries refer to the deep counsels of God hitherto secret, but now revealed to His saints. Knowledge, to truths long known.

faith ... remove mountains--(Mt 17:20; 21:21). The practical power of the will elevated by faith [Neander]; confidence in God that the miraculous result will surely follow the exercise of the will at the secret impulse of His Spirit. Without "love" prophecy, knowledge, and faith, are not what they seem (compare 1Co 8:1, 2; Mt 7:22; Jas 2:14; compare 1Co 13:8), and so fail of the heavenly reward (Mt 6:2). Thus Paul, who teaches justification by faith only (Ro 3:4, 5; Ga 2:16; 3:7-14), is shown to agree with James, who teaches (Jas 2:24) "by works" (that is, by LOVE, which is the "spirit" of faith, Jas 2:26) a man is justified, "and not by faith only."