Ligonier Ministries is publishing, through their blog, an out-of-print book by the late John Gerstner, Theology for Everyman:
Is it not clear why a layman must necessarily be a theologian? Is there anyone, layman or otherwise, who does not need to know God? Does the Scripture not say, “This is life eternal, that they might know Thee, the only true God, and Jesus Christ, whom Thou hast sent” (John 17:3)? It is no mere option, then, with a layman whether or not he will be a theologian, or whether he will have eternal life or not; it is not an option with him whether he will know God or not. The knowledge of God is necessary to eternal life. And if eternal life is necessary for every man, then theology is also necessary for every man.
More here.
