Spiritual understanding, to begin with, is the combination of two things. First of all, it is the result of the direct action of the Spirit of God upon the spirit of man. By nature our spirit is in death, and the Spirit of God acts to raise it from the dead and bring it into life. And it is our spirit which is the organ of spiritual understanding. If we are normal, we have a natural understanding, but by nature we do not possess this faculty, this organ of spiritual understanding. It is dead, or dormant, until the Spirit of God acts upon it, and then we are aware that we have a new faculty, a faculty of discrimination. We know from that moment, without being told anything about it, what we should do and what we should not do, what is right and what is wrong. It is a new faculty, but that faculty is indwelt and actuated by the Spirit of God, and is not acting independently. “The Spirit himself beareth witness with our spirit, that we are children of God” (Romans 8:16).
Therefore the combination of these two things, the resurrection into life of our own spirit and becoming indwelt by the Spirit of God, constitutes the organ and function of spiritual understanding. It begins in simple ways, but education in the Christian life proceeds upon that basis, and that alone.
There is a link formed by this action of the Holy Spirit between knowledge and conscience. Note that, for it is a very important thing. There is a link between knowledge and conscience, which is a new conscience or consciousness. That explains the tragedy of many Christian lives. They have a lot of knowledge without any conscience about it. It is not a knowledge which produces a consciousness of life, and so there is inconsistency and contradiction. They know the teaching, the doctrine, the truth and what the Word of God says, but there is no deep exercise in their hearts that gives them, on the one side, a bad time for any inconsistency and, on the other side, great joy in realizing that they are being well-pleasing unto the Lord. This link, you see, is what is meant by spiritual understanding. ‘I KNOW that that is mere knowledge, information, or truth, but I UNDERSTAND when the thing affects me, when it touches my life, and when it brings me up short on matters.’ That is spiritual understanding.