This world is full of sin and iniquity on every hand. We may hear profanity as we pass along the street, or we may see iniquity before our eyes daily as we come in contact with the world, we may pick up a secular paper and read of murder and theft, and thus these evil thoughts may enter into our minds, but they do not conceive or take root in our hearts. They are brought into captivity and banished from us. If when reading or hearing of a murder or theft, someone should see an opportunity to commit a similar deed and resolve in his heart that he would do so at his first opportunity, that person would have conceived the thought in his heart, and in the sight of God he would be a murderer or a thief, even though he never had the opportunity to carry out the design. The heart that is purified by the cleansing blood of Christ and momently kept in the efficacy of that blood, is the sacred dwelling-place of the Holy Spirit, who has the full and exclusive control of the heart. As long as our will is kept in line with the will of God the Holy Spirit will abide. The word of God says, "Greater is he that is in you than he that is in the world," and, "No man can enter into a strong man's house and spoil his goods, except he will first bind the strong man." The strong man--the Holy Spirit--is in his own house, and it is impossible for sin to enter in unless we by our own will consent to it. The word of God speaks of the Holy Spirit as the seal. This thought is practically illustrated by the common use of a seal in canning fruit. We may be ever so careful with fruit in getting it properly prepared for the can, but if we set it away without the seal, it will not be long until the fruit is spoiled. It requires the seal to keep the fruit from spoiling. There is something in the air which, if not excluded, will spoil the fruit. The use of the seal is to exclude the air. So it is with our heart. Justification inducts us into Christ; sanctification purifies our hearts and seals us in him; now when sin would come in contact with our hearts and defile it, there is something there, the Holy Spirit, the seal, which keeps sin from entering in. "If we walk in the light, as he is in the light, we have fellowship one with another and the blood of Jesus Christ his Son cleanseth us from all sin."--1 John 1:7. Notice the word "cleanseth." It is in the present tense. By our walking in the light, which signifies our perfect obedience continually to all the known will of God, our heart is kept in line with God's will and hence under the provisions of his grace--the sin-cleansing blood of Jesus. Thus the perpetual cleansing keeps our heart pure. By the inwrought work of sanctification we =obtain= this purity, and by our obedience to God, walking in the light, we =retain= it.