Even in the beginning of its renovated life, when it first finds the blessedness of forgiveness, the soul experiences a degree of peace. But, compared with what it is subsequently, it is limited both in degree and permanency. At the early period to which we now refer, the soul finds rest from the condemnation of past sins, without finding rest from the sharpness of inward conflicts, from doubts, uncertainties, and heavy temptations. As it advances in religious experience, the elements of rest develop themselves. When, by the crucifixion of self and the full resurrection of a new and purified spirit, it has become one with its heavenly Father, it then has a peace or rest approaching that of the heavenly world. "Thou wilt keep him in perfect peace," says the prophet Isaiah, "whose mind is stayed on Thee, because he trusteth in Thee.”
It is important to understand correctly in what true rest or peace of the soul consists. There is a rest which is more so in appearance than reality; just as there is a semblance, a counterfeit of humility, of benevolence, and of other Christian graces. There are some persons whose apparent rest is to be ascribed to natural inertness or stupidity, and not to the sanctified adjustment of their powers. The true rest, however, is not to be regarded as identical with inaction.
The rest of the soul, in the highest spiritual sense of the terms, is that state of the soul, whether it be in repose or in action, which is in harmony with God. There is only one right position of the soul. All others must necessarily be wrong. And that position is one where the creature is brought into perfect adjustment with the Creator, by deriving its perceptions from God, by merging its affections in God's affections, and by harmonizing its will with God's will. In such a state of the soul there must necessarily be rest, if God has rest.
— edited from A Treatise on Divine Union (1851) Part 8, Chapter 1.
