There are some respects in which the idea of warfare applies to the life of all, and there are other respects in which we are called to make our life a warfare of our own free and deliberate choice.
I. Take, for example, the period of infancy and childhood, and here we have emphatically the battle (1) of weakness. Later comes (2) the battle of ignorance, (3) the battle of passion, (4) the battle of necessity and the battle of society conjoined. We observe (a) that the struggle is not equally intense and painful in us all, and (b) that it is not all struggle with any. No human spirit could bear a perpetual strain, no human heart could support a perpetual pressure.
II. Scripture commands us to make our life a warfare of our own free and deliberate choice. Notice the manner in which this spiritual warfare is to be carried on. (1) The first thing to be done is to put ourselves in alliance with Christ. It cannot be accomplished in any other way. The battle must begin at the cross, and the warfare must be carried on, from beginning to end, under the covert of atoning blood. (2) It must be maintained in a spirit of prayer, for it is this that preserves our reliance on God, and makes us strong in the strength which is in Christ Jesus. It is such a conflict as requires a better strength than our own, and if this were all we had to depend on it would be useless making the attempt. (3) The struggle must be maintained honestly. That is to say, we must direct our attention to the resistance of allevil, and to the positive cultivation of allgood. (3) We must maintain the warfare cheerfully, not as a dire necessity, but as that which is evidently proper and right, that in which our reason and heart were fully engaged, as that which is daily bringing us nearer to God, and making us more and more meet to be partakers of the inheritance of the saints in light.
A. L. Simpson, The Upward Path,p. 57.