Therefore I shall again repeat the doctrine of the Trinity, as it is positively affirmed in Scripture:  that God is there expressed in three different names, as Father, as Son, and as Holy Ghost:  that each of these is God, and that there is but one God.  But this union and distinction are a mystery utterly unknown to mankind.

This is enough for any good Christian to believe on this great article, without ever inquiring any farther:  And, this can be contrary to no man’s reason, although the knowledge of it is hid from him.

But there is another difficulty of great importance among those who quarrel with the doctrine of the Trinity, as well as with several other articles of Christianity; which is, that our religion abounds in mysteries, and these they are so bold as to revile as cant, imposture, and priestcraft.  It is impossible for us to determine for what reasons God thought fit to communicate some things to us in part, and leave some part a mystery.  But so it is in fact, and so the Holy Scripture tells us in several places.  For instance:  the resurrection and change of our bodies are called mysteries by St Paul:  and our Saviour’s incarnation is another:  The Kingdom of God is called a mystery by our Saviour, to be only known to his disciples; so is faith, and the word of God by St Paul.  I omit many others.  So, that to declare against all mysteries without distinction or exception, is to declare against the whole tenor of the New Testament.

There are two conditions that may bring a mystery under suspicion.  First, when it is not taught and commanded in Holy Writ; or, secondly, when the mystery turns to the advantage of those who preach it to others.  Now, as to the first, it can never be said, that we preach mysteries without warrant from Holy Scripture, although I confess this of the Trinity may have sometimes been explained by human invention, which might perhaps better have been spared.  As to the second, it will not be possible to charge the Protestant priesthood with proposing any temporal advantage to themselves by broaching or multiplying, or preaching of mysteries.  Does this mystery of the Trinity, for instance, and the descent of the Holy Ghost, bring the least profit or power to the preachers?  No; it is as great a mystery to themselves as it is to the meanest of their hearers; and may be rather a cause of humiliation, by putting their understanding in that point upon a level with the most ignorant of their flock.  It is true indeed, the Roman church hath very much enriched herself by trading in mysteries, for which they have not the least authority from Scripture, and were fitted only to advance their own temporal wealth and grandeur; such as transubstantiation, the worshipping of images, indulgences for sins, purgatory, and masses for the dead; with many more:  But, it is the perpetual talent of those who have ill-will to our Church, or a contempt for all religion, taken up by the wickedness of their lives, to charge us with the errors and corruptions of Popery, which all Protestants have thrown off near two hundred years:  whereas, those mysteries held by us have no prospect of power, pomp, or wealth, but have been ever maintained by the universal body of true believers from the days of the apostles, and will be so to the resurrection; neither will the gates of hell prevail against them.