Man ought to love nothing but God alone. And seeing that God alone is to be loved, it follows, that he who loves himself, is an idolator, and makes himself as God. What every one loves, in that his heart is fixed; and where his heart is fixed, thereto pays he his devotion. He is a servant of it, whatsoever it be, and devoted to it. Neither can we but be taken with the love and servitude of some thing or other, so as we become servants thereof, by despoiling ourself of our proper liberties; and consequently we have in this broken and divided state, as many lords who we are subject to as, we have objects whom we love. But if your love, O Man! be sincerely and simply directed towards God, then you are subject to no other Lord; then are you enslaved to no other object; and it is manifest you are hereby at liberty. Wherefore you must be very circumspect, that you follow after nothing that may hinder the divine love in you; and that you suffer not your soul to wander or your affections to run out into any of the creatures.
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He who seeks himself every where, and in all things, and follows after nought but his own profit, praise, and honour, never attains to tranquility; for always something or other meets him that brings perturbation. Therefore believe not that the increase of your wealth, fame, and honor in this world, is to you good and profitable; but rather set before you always the best things, the heavenly treasures, and immortal honours and glories, and contemn all such mean and passing things, and strive for this end to extirpate the very root of corruption, which hinders you in the pursuit of the love of God. For as much as in this love you shall find all the riches of God, and all the pleasures of paradise to be contained.
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From True Chrstianity or, the whole economy of God towards man in four books, by John Arndt, translated by Anthony William Boehm in 1712, from a copy printed in 1809