Now, mark you, if you are living for yourself, if you are living for gain, if selfishness be the object of life, or if you are pursuing an unhallowed calling, if there is anything about your mode of business which is contrary to the mind and will of God and sound doctrine, you cannot expect God to aid you in sin, nor will he do it. Neither can you ask him to pander to your lusts, and to assist you in the gratification of your own selfishness. But if you can truly say, “I live to the glory of God, and the ordinary life that I lead I desire to consecrate to his glory entirely,” then may you take this promise home to yourself, “I will not fail thee, nor forsake thee.”
But, mark you, there is another matter. We must, if we are to have this promise, take God into our calculations. A great many persons go about their supposed lifework without thinking about God. I have heard of one who said everybody had left him, and some one said, “But surely, as a Christian, God has not failed you?” “Oh,” said he, “I forgot God.” I am afraid there are many who call themselves Christians, and yet forget God in common life. Among all the forces that a man calculates upon when he engages in an enterprise, he should never omit the chief force: but often it is so with us. We enquire, “Am I competent for such a work? I ought to undertake it, but am I competent?” And straightway there is a calculation made of competences. And in these competences there is no item put down, “Item, the promise of a living God. Item, the guidance of the Spirit.” These are left out of the calculation.
Remember that if you willfully omit them you cannot expect to enjoy them. You must walk by faith if you are to enjoy the privileges of the faithful. “The just shall live by faith,” and if you begin to live by sense, you shall join the weeping and the wailing of those who have gone to broken cisterns, and have found them empty; and your lips shall be parched with thirst, because you have forgotten the fountain of living waters to which you should have gone. Do you, brethren and sisters, habitually take God into your calculations? Do you calculate upon omniscient direction and omnipotent aid? I have heard of a certain captain who had led his troops into a very difficult position, and he knew that on the morrow he should want them all to be full of courage; and so, disguising himself, at nightfall he went round their tents, and listened to their conversations, until he heard one of them say, “Our captain is a very great warrior, and has won many victories, but he has this time made a mistake; for see, there are so many thousands of the enemy, and he has only so many infantry, so many cavalry, and so many guns.”
The soldier made out the account, and was about to sum up the scanty total when the captain, unable to bear it any longer, threw aside the curtain of the tent, and said, “And how many do you count me for, sir?”—as much as to say, “I have won so many battles that you ought to know that my skill can multiply battalions by handling them.” And so the Lord hears his servants estimating how feeble they are, and how little they can do, and how few are their helpers; and I think I hear him rebukingly say, “But how many do you count your God for? Is he never to come into your estimate? You talk of providing, and forget the God of providence; you talk of working, but forget the God who works in you to will and to do of his own good pleasure.”
How often in our enterprises have prudent people plucked us by the sleeve, and said we have gone too far. Could we reckon upon being able to carry out what we had undertaken? No, we could not reckon upon it, except that we believed in God, and with God all things are possible. If it be his work, we may venture far beyond the shallowness of prudence into the great deeps of divine confidence, for God who warrants our faith, will honour it ere long. Oh, Christian, if you can venture, and feel it to be no venture, then may you grasp the promise, “I will not fail thee, nor forsake thee.”
-- from Charles Haddon Spurgeon, The Metropolitan Tabernacle Pulpit Sermons “Strengthening Medicine for God’s Servants,” vol. 21, no. 1,214 (London: Passmore & Alabaster, 1875), 52-55.