one of the facts which is clear enough is this, that the Lord usually adapts means to ends, from which the plain lesson is, that we shall be likely to accomplish most when we are in the best spiritual condition; or in other words, we shall usually do our Lord’s work best when our gifts and graces are in good order, and we shall do worst when they are most out of trim. This is a practical truth for our guidance, when the Lord makes exceptions, they do but prove the rule.
We are, in a certain sense, our own tools, and therefore must keep ourselves in order. If I want to preach the gospel, I can only use my own voice; therefore I must train my vocal powers. I can only think with my own brains, and feel with my own heart, and therefore I must educate my intellectual and emotional faculties. I can only weep and agonise for souls in my own renewed nature, therefore must I watchfully maintain the tenderness which was in Christ Jesus. It will be in vain for me to stock my library, or organise societies, or project schemes, if I neglect the culture of myself; for books, and agencies, and systems, are only remotely the instruments of my holy calling; my own spirit, soul, and body, are my nearest machinery for sacred service; my spiritual faculties, and my inner life, are my battle axe and weapons of war.
C. H. Spurgeon, Lectures to My Students: A Selection from Addresses Delivered to the Students of the Pastors’ College, Metropolitan Tabernacle., vol. 1 (London: Passmore and Alabaster, 1875), 1–2.