1 Thessalonians 5:21
Prove all things; hold fast that which is good.
Faith and reason are, as it were, two keys which God has given us with which to unlock all spiritual mysteries. It is as if I had a drawer in which were stored away my valuable papers. The cabinet maker gives me two keys to my drawer, telling me that both keys will generally unlock the drawer, but always, if one will not, the other will — that therefore I must keep them securely, and keep them always tied together. But I untie and separate them, and, for safe keeping, place one key carefully away in the drawer itself and lock it up with the other key. With this other key I lock and unlock the drawer at pleasure. But the time comes at length when the key I have will not unlock the drawer, and now I need the other; but I have locked it up and cannot get it. Just so faith and reason are two keys that God, our Maker, has given us with which to unlock all spiritual mysteries. Generally, either will unlock and explain all difficulties in Revelation and Christian experience; but always, if the one fails, the other will unlock the mystery. But here is a man that goes and locks his faith up in his reason; and presently he encounters a spiritual truth which his reason will not explain or unlock — it transcends human reason. You tell him, for example, that he must believe in the Trinity, in regeneration, in the resurrection of the body. "But," says he, "I cannot — they are unreasonable." And why can he not believe these spiritual truths? Simply because he has gone and locked his faith up in his reason, and will not accept any truth which he cannot comprehend and which his reason will not fully explain of itself without the aid of faith. The rationalist is he who locks his faith up in his reason. Now it may be, and is, just as bad to lock your reason up in your faith. There, for instance, is the poor deluded Romanist, who believes implicitly anything that his Church teaches, whether reasonable or unreasonable. You remonstrate with him for believing in transubstantiation, in the virtue of relics, in the absurd traditions of his Church. You tell him these things are unreasonable. "So they may be," he replies, "but I believe them nevertheless, for the Church teaches them, and I believe whatever the Church teaches." And why does he believe such absurdities? Simply because he has locked his reason up in his faith and given the Pope the key — and whatever the Pope or the Church or his bishop teaches he believes implicitly, whether it be reasonable or unreasonable. It is impossible for one to be a true Roman Catholic without locking his reason up in his faith. But God demands that we shall use both our faith and our reason, and keep them both joined together. Doing this we shall be preserved from rationalism on the one hand, and from credulity and superstition on the other. Now God does not demand that we shall believe in anything that contradicts our reason; but He does demand that we shall believe in truths that transcend human reason. If the Bible should teach that black is white, that right is wrong, that a thing can be and not be at the same time, I would not and could not believe it, because it would plainly contradict my reason. But when it teaches that there is a God, a Trinity, a soul in this body, a heaven prepared for it, I may not and do not fully comprehend these spiritual truths; but I do not decline to believe them on that ground; for while they do transcend my reason, they do not contradict it. The Roman Catholic believes many truths that contradict human reason; the rationalist will believe no truth which transcends human reason; the true intelligent Christian believes nothing that will contradict, but many things that transcend, human reason. The first locks his reason up in his faith; the second locks his faith up in his reason; the third uses both his faith and his reason and keeps them ever joined together.
Parallel VersesKJV: Prove all things; hold fast that which is good.