"For there are three that bear record in heaven, the Father, the Word, and the Holy Spirit--and these three are one." 1 John 5:7
All God's people are led into a knowledge of the Trinity; not indeed by metaphysical reasoning or subtle arguments addressed to the understanding. The Spirit teaches them, not by reasoning addressed to the head, but by the power and dew of divine truth resting upon the heart. All God's people learn the doctrine of the Trinity in their souls. They learn, under divine teaching, the authority, justice, majesty, holiness, and in due time feel the love of God the FATHER. They learn the Godhead of CHRIST in their souls, by seeing and feeling the power of his blood, as the blood of God (Acts 20:28), and his righteousness as the "righteousness of God." And they learn the Deity and Personality of the HOLY SPIRIT by feeling the divine power of his operations on their hearts. They learn also that he is God, by perceiving how he scrutinizes all their actions, brings to light every secret thought, and applies passages of Scripture to their souls, which none but God could produce, or so suitably apply.
And when they are thus led by divine teaching, into the Three Persons of the Godhead, they are brought to know and feel in the depths of conscience, that there are Three Persons, equal in power, will, essence, and glory, and but one Jehovah. Now these truths no man can learn in a saving manner, except by this special teaching. He may know all this, and much more than this, in his understanding and judgment; but a sensible realization of the power of these things in the conscience, a divine melting of the heart under them, with an enlargement of soul, and an experimental enjoyment of them, is the alone fruit of God's teaching resting on him, so as to make him "a new creature" in Christ.