Jamieson, Fausset and Brown on 2 Corinthians 4:13

13. Translate as Greek, "BUT having," &c., that is, not withstanding the trials just mentioned, we having, &c.

the same spirit of faith, according as it, &c.--Compare Ro 8:15, on the usage of "spirit of faith." The Holy Spirit acting on our spirit. Though "death worketh in us, and life in you" (2Co 4:12), yet as we have the same spirit of faith as you, we therefore [believingly] look for the same immortal life as you [Estius], and speak as we believe. Alford not so well translates, "The same ... faith with that described in the Scriptures" (Psa 116:10). The balance of the sentence requires the parallelism to be this, "According to that which is written, I believed, and therefore have I spoken; we also believe, and therefore speak," namely, without fear, amidst "afflictions" and "deaths" (2Co 4:17).