AW Pink on the two natures of the believer
Jacob was a believer in God- a careful study of his prayer as recorded in Genesis 32:9-12 evidences that. But though Jacob was a believer there still remained the "flesh," the old evil nature in him. And to this he gave way. The flesh is ever unbelieving, and where it is not constantly judged breaks forth in God-dishonouring activities. The clearest exemplification and demonstration of the two natures in the believer is to be seen in the history of Jacob recorded faithfully by the Holy Spirit not for our emulation but for our "warning." The same two natures are in every child of God today, the spiritual and the carnal, the one which believes God and the other which disbelieves.
AW Pink, Gleanings in Genesis, p.288
This is of course from one of Pink's earliest works and he may have changed his position on this later.
AW Pink's Calvinism could get really ugly at times, nevertheless there are some real gems in his writings. I cannot help but recommend his expository works to the discerning reader.