Watch and Pray: It Takes Both
"Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak" (Matt. 26:41). Prayer of itself is not sufficient: we have not fully discharged our duty when we have asked God to lead us not into temptation, but deliver us from evil. We must "watch," be on the alert, noting the direction of our desires, the character of our motives, the tendency of things which may be lawful in themselves, the influence of our associations. It is our inner man which we most need to watch: "Keep thy heart with all diligence, for out of it are the issues of life" (Prov. 4:23). Then, if we are faithful and diligent in "watching," out of a sense of our personal weakness and insufficiency, it is in order to "pray," counting on the help of our gracious God to undertake for us. To "pray" without "watching" is only to mock God, by seeking to shelve our responsibility.
Prayer was never designed by God as a substitute for personal effort and diligence, but rather as an adjunct thereto - to seek divine grace for enabling us to be dutiful and faithful. "Continue in prayer, and watch in the same with thanksgiving" (Col. 4:2). Not only does God require us to "watch" before we pray, but we are also to "watch" immediately after. And again we say, that which we most need to watch is ourselves. There is a traitor within our own breast, ever ready and desirous of betraying us if allowed the opportunity of so doing. Who had thought that such an one as David would ever experience such a fearful fall as he had! Ah, my reader, not even a close walk with God, or a long life of eminent piety, will eradicate or even change the sinful nature which still abides in the saint. So long as we are in this world we are never beyond the reach of temptation, and nought but watchfulness and prayer will safeguard us from it."
The Life of David, A.W. Pink (Vol. 2, Ch. 52, His Terrible Sin [2 Samuel 11])