John MacArthur, Hebrews Commentary, Moody, 1983, p. 331.
In one sense it is possible “to be so heavenly minded that we are of no earthly good.” But in a much deeper sense, it is impossible to be of any real earthly good unless we are heavenly minded. Only the heavenly minded will have the patience to continue faithful in God’s work when it becomes hard, unappreciated and seemingly unending. There is no greater cure for discouragement, fatigue or self-pity than to think of being in the presence of the Lord one day and of spending eternity with Him. We should make no apology for being heavenly minded.
John MacArthur, Hebrews Commentary, Moody, 1983, p. 331.