The Kingdom of God as established by Christ is at once a visible Church in this world, and an invisible spiritual Kingdom of grace within the soul. External adherence to the visible Kingdom demands also that Christ reign by grace within the soul. But this interior grace does not dispense a man from accepting the will of Christ once he is aware of it, nor from the obligation to join the visible Kingdom established by Him in this world. Christ distinctly said, “I will build my Church”; and again, “If a man will not hear the Church, let him be as the heathen.” He was obviously referring to the authority of a visible Church. He also likened His Church to a net holding good and bad fish. This cannot refer to a Kingdom of spiritual and invisible grace only, for bad fish are not in a state of grace.
Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty