The Great Business of the Christian Life

Keep your heart with all vigilance, for from it flow the springs of life. (Proverbs 4:23)

Heart-work is hard work, indeed. To shuffle over religious duties with a loose and heedless spirit will cost no great pains, but to set yourself before the Lord, and tie up your loose and vain thoughts to a constant and serious attendance upon Him, will cost you something. To attain a facility and dexterity of language in prayer... is easy; but to get your heart broken for sin while you are confessing it and melted with free grace while you are blessing God for it, to be really ashamed and humbled through the apprehensions of God's infinite holiness, and to keep your heart in this frame not only in but after duty will surely cost you some groans and travailing pain of soul. To repress the outward acts of sin and compose the external part of your life in a laudable and comely manner is no great matter....But to kill the root of corruption within, to set and keep up a holy government over your thoughts, ... this is not easy.

It is a constant work. ... This labor and our life end together. It is with a Christian in this business as it is with seamen who have sprung a leak at sea: If they tug not constantly at the pump, the water increases upon them and will quickly sink them. It is in vain for them to say, "The work is hard and we are weary." There is no time or condition in the life of a Christian which will suffer an intermission of this work.
--John Flavel (1630-1691)