The witness of our own spirit is that self-judgment which we are rationally able to pronounce, in the light of consciousness and Scripture, that we are the children of God. This is a logical inference, drawn from the fruits we find, by self-examination, in our minds and external conduct.
But besides this, is there not felt in every deep religious experience, a simple, firm assurance, like an intuition, by which we are made to feel calmly certain that all is blessedly right between God and our own soul? Does not this assurance seem to come into the heart as from some outer source? Does it not come as in answer to prayer, and in direction, as if from him to whom we pray? Scripture surely makes the assuring and witnessing act of the Spirit to be as immediate and direct as the justifying or regenerating acts. Hereby, then, we have the witness of God's Spirit, concurrent with the witness of our own spirit, testifying to the work of our justification and adoption. "The Spirit itself beareth witness with our spirit that we are the children of God." Rom. viii, 16.
— Daniel D. Whedon, "The Doctrines of Methodism" Bibliotheca Sacra, April, 1862.