I often find biographies to be more helpful than many strictly theological books, insomuch as through them one sees how theologians and ministers applied their beliefs practically. For instance, having today finished reading The Life of A. W. Pink, I find myself much affected by the picture of his many strengths amid certain weaknesses. Particularly notable were his bouts of depression and sense of spiritual isolation which accompanied his work.
The fact that he who literally "wrote the book" on God's sovereignty, who memorized thousands of scriptures and read as much as one-million pages of theological literature, was not above the need for the special comfort of the Spirit, is a humbling reminder to "look unto Jesus" for manifestations of His gracious kindness. The Christian's hope of consolation is not found in all the treatises ever penned, but in the person of the Spirit who alone vitally applies doctrinal truths to the hearts of believers, thereby strengthening their faith.
The painful lesson Pink passed on was to persevere in hope, trusting God to "work all things for good" despite the present lack of understanding. Better to be nearly bereft of learning and yet take refuge in the Spirit of grace, than to rely on one's stock of biblical information to weather the storm! That man will surely fall who uses the Word merely as a cane, trusting his own weak arm to stand upon it. His faith must not be in his own strength to grasp the Truth, but in the Shepherd who wields it as a crook, looping it about His sheep and bringing them to rest in His pasture.
In conclusion, Pink is a diamond: visibly complex and yet utterly singular, possessing flaws and yet exceeding in value the hundreds of frail and dim panes of glass which comprise many modern pulpits. There is much to be learned, both from the errors and the achievements of his life, thus I highly recommend Iain Murray's biography of him.