How diligently the cavalry officer keeps his sabre clean and sharp; every stain he rubs off with the greatest care. Remember you are God's sword, His instrument--I trust, a chosen vessel unto Him to bear His name. In great measure, according to the purity and perfection of the instrument, will be the success. It is not great talents God blesses so much as likeness to Jesus. A holy minister is an awful weapon in the hand of God.
--Robert Murray McCheyne, quoted in C. H. Spurgeon, Lectures to My Students (Zondervan 1954), 8