151. Believing in the Lord is not just a matter of acknowledging Him, but includes keeping His commandments. Merely to acknowledge Him only demands some thought on the part of the understanding, but to keep His commandments requires acknowledgment too on the part of the will. The human mind is made up of the understanding and the will. It is the function of the understanding to think, of the will to act. So as long as a person's acknowledgment is merely in thought on the part of the understanding, he approaches the Lord with no more than half his mind; but when he acts, then he does so with his whole mind, and that is what believing is. Otherwise a person can split his heart in two, and force its surface to soar aloft, while its flesh sinks downwards; and so he flies like an eagle between heaven and hell. Yet he does not follow his gaze, but the delights of the flesh; and since they lie in hell, he flies down there, and after indulging in his pleasures there and tasting the demons' new wine, he puts on a jolly face, and his eyes sparkle as if with fire, so as to impersonate an angel of light. This is the satanic appearance after death of the people who acknowledge the Lord, but do not keep His commandments.