"Oil for the light." --Exodus 25:6
My soul, how much thou needest this, for thy lamp will not long continue to burn without it. Thy snuff will smoke and become an offence if light be gone, and gone it will be if oil be absent. Thou hast no oil well springing up in thy human nature, and therefore thou must go to them that sell and buy for thyself, or like the foolish virgins, thou wilt have to cry, "My lamp is gone out." Even the consecrated lamps could not give light without oil; though they shone in the tabernacle they needed to be fed, though no rough winds blew upon them they required to be trimmed, and thy need is equally as great. Under the most happy circumstances thou canst not give light for another hour unless fresh oil of grace be given thee.
It was not every oil that might be used in the Lord's service; neither the petroleum which exudes so plentifully from the earth, nor the produce of fishes, nor that extracted from nuts would be accepted; one oil only was selected, and that the best olive oil. Pretended grace from natural goodness, fancied grace from priestly hands, or imaginary grace from outward ceremonies will never serve the true saint of God; he knows that the Lord would not be pleased with rivers of such oil. He goes to the olive-press of Gethsemane, and draws his supplies from Him who was crushed therein. The oil of gospel grace is pure and free from lees and dregs, and hence the light which is fed thereon is clear and bright. Our churches are the Saviour's golden candelabra, and if they are to be lights in this dark world, they must have much holy oil. Let us pray for ourselves, our ministers, and our churches, that they may never lack oil for the light. Truth, holiness, joy, knowledge, love, these are all beams of the sacred light, but we cannot give them forth unless in private we receive oil from God the Holy Ghost.
by Charles H. Spurgeon