h, 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.

In this blessed grace, no evil thought can enter our heart unless by our
consent. We have willed it so that we forsake all sin and turn to God;
thus his grace of justification has found its way into our heart. Then
by a definite consecration we willed it so that the cleansing blood of
Jesus should purify our heart from inborn depravity, and his grace of
sanctification has found its way within, and has brought the glorious
heavenly guest, the Holy Spirit, there to abide. Now as we continue to
walk in this light we are kept from sin. By our will we either open or
close our heart toward God. The will is the entrance and door. The grace
of God is free, and more abundant than the sunshine that lights and
warms this earth. All of this sunshine may be kept out of the room if we
will to have it so. We can darken the windows and doors, and keep every
ray of light out, or we can have abundant sunshine if we will, by simply
removing the obstacles. So it is with the illimitable grace of God. If
we open up wide the door of our heart--our will--and keep it open
continually, the grace will flow in and keep out everything that is not
like heaven. "For God, who commanded the light to shine out of darkness,
hath shined in our hearts, to give the light of the knowledge of the
glory of God in the face of Jesus Christ. But we have this treasure in
earthen vessels, that the excellency of the power may be of God, and not
of us."--2 Cor. 4:6, 7.

If we close the door