
To be "in the will of God" or to "live in God's will" is never an issue of one thing, one decision, or one demonstration of yieldedness. It is a matter of attitude--of a mindset according to which one lives his life.
To be in the will of God is to take His will as the general, governing rule and dominating principle of one's whole life. It is to be willing to do anything that God desires, when, where, and how God desires.
Christ is our example. He did always those things that pleased the Father (John 8.29). That was His attitude, His general rule of life, and the dominating principle in every decision He made. This is the "mind" that God wants in every one of His sons (Php 2.6-11).
Lewis Sperry Chafer gives a very succinct description of the elements of this mindset that should find immediate reproduction in the believer:
Since our heavenly Father is perfect and "omnibenevolent" (all good and only good), His children can rest assured that He delights only in that which is best for each child, and that He will never impose upon him or be careless. Because of this, living in the will of God as Christ did (with His mindset) is simply a matter of faith. Do we really believe what God said, so much so that we adjust our entire lives to live according to the same?
And let's always remember that this kind of life that is yielded always to the will of God is a "sacrificial" life, and therefore it is voluntary. Christ rescued us from slavery to sin; He Himself is no taskmaster. The rescued and redeemed, however, may willingly choose, by personal dedication to the Master, to serve as His bondslaves. Our words are those of Exodus 21.5-6: "I love my Master . . . I will not go out free . . ."
This type of sacrificial life yielded to the will of God isn't necessarily painful; but it is always good, acceptable, and perfect (Rom 12.1-2). Chafer said, "Some pain may lie in the path, but the prevailing note is one of joy and the experience of the heart is peace."
Lewis Sperry Chafer, Pneumatology, vol. 6 of Systematic Theology (Dallas, TX: Dallas Theological Seminary, 1976), pp. 257-59.