The text is Paul's battle-cry, which he opposed to the Judaising disturbers in Galatia. They said 'Do this and that; labour at a round of observances; live by rule.' Paul said, 'No! That is of no use; you will make nothing of such an attempt nor will ever conquer evil so. Live by the spirit and you will not need a hard outward law, nor will you be in bondage to the works of the flesh.' That feud in the Galatian churches was the earliest battle which Christianity had to fight between two eternal tendencies of thought--the conception of religion as consisting in outward obedience to a law, and consequently as made up of a series of painful efforts to keep it, and the conception of religion as being first the implanting of a new, divine life, and needing only to be nourished and cared for in order to drive forth evils from the heart, and so to show itself living. The difference goes very far and very deep, and these two views of what religion is have each their adherents to-day. The Apostle throws the whole weight of his authority into the one scale, and emphatically declares this as the one secret of victory, 'Walk in the Spirit, and ye shall not fulfil the lusts of the flesh.' I. What it is to walk in the Spirit. The thought which is but touched upon here is set forth more largely, and if we may so say, profoundly, in the Epistle to the Romans (chap. viii.). There, to walk after the flesh, is substantially the same as to be carnally minded, and that 'mind of the flesh' is regarded as being by fatal necessity not 'subject to the law of God,' and consequently as in itself, with regard to future consequences, to be death. The fleshly mind which is thus in rebellion against the law of God is sure to issue in 'desires of the flesh,' just as when the pressure is taken off, some ebullient liquid will bubble. They that are after the flesh of course will 'mind the things of the flesh.' The vehement desires which we cherish when we are separated from God and which we call sins, are graver as a symptom than even they are in themselves, for they show which way the wind blows, and are tell-tales that betray the true direction of our nature. If we were not after the flesh we should not mind the things of the flesh. The one expression points to the deep-seated nature, the other to the superficial actions to which it gives rise.