The motive which impels us to assent to a truth must lie in reason, not in revelation, which, like all authority and experience, is merely the way by which we attain the knowledge of the truth; it is a means of instruction, not a ground of conviction.  All faith has knowledge and understanding for its conditions, and is rational conviction.  Before we can put our trust in the Scriptures, we must be convinced that they were in fact written by the authors to whom they are ascribed, and must consider whether these men, their deeds, and their works, were worthy of God.  The fact that God’s inmost being is for us inscrutable does not make him a mystery, for even the common things of nature are known to us only by their properties.  Miracles are also in themselves nothing incomprehensible; they are simply enhancements of natural laws beyond their ordinary operations, by supernatural assistance, which God vouchsafes but rarely and only for extraordinary ends.  Toland explains the mysteries smuggled into the ethical religion of Christianity as due to the toleration of Jewish and heathen customs, to the entrance of learned speculation, and to the selfish inventions of the clergy and the rulers.  The Reformation itself had not entirely restored the original purity and simplicity.

Thus far Toland the deist.  In his later writings, the five Letters to Serena, 1704, addressed to the Prussian queen, Sophia Charlotte, and the Pantheisticon (Cosmopoli, 1720), he advances toward a hylozoistic pantheism.

The first of the Letters discusses the prejudices of mankind; the second, the heathen doctrine of immortality; the third, the origin of idolatry; while the fourth and fifth are devoted to Spinoza, the chief defect in whose philosophy is declared to be the absence of an explanation of motion.  Motion belongs to the notion of matter as necessarily as extension and impenetrability.  Matter is always in motion; rest is only the reciprocal interference of two moving forces.  The differences of things depend on the various movements of the particles of matter, so that it is motion which individualizes matter in general into particular things.  As the Letters ascribe the purposive construction of organic beings to a divine reason, so the Pantheisticon also stops short before it reaches the extreme of naked materialism.  Everything is from the whole; the whole is infinite, one, eternal, all-rational.  God is the force of the whole, the soul of the world, the law of nature.  The treatise includes a liturgy of the pantheistic society with many quotations from the ancient poets.