I noticed something that may be helpful to some. Besides being told Jesus will "purify" the heart, we see a point being made that there is a dividing line between temporal life and everlasting death. God gives us a period of probation in which to decide whom we will serve permanently. When that probation is up, there is no turning back. With Judas we see not only when that occurred, but we also see who closed his probation, it was not God.
In surprise and confusion at the exposure of his purpose, Judas rose hastily to leave the room. "Then said Jesus unto him, That thou doest, do quickly. . . . He then having received the sop went immediately out: and it was night." Night it was to the traitor as he turned away from Christ into the outer darkness. Until this step was taken, Judas had not passed beyond the possibility of repentance. But when he left the presence of his Lord and his fellow disciples, the final decision had been made. He had passed the boundary line.
Judas made the decision that was irreversible. His heart could no longer be brought to repentance. Not because God would not reveal grace, but because grace could no longer reach the heart that was hardened to that degree. It is our choice to close our probation when it comes to rejecting truth and the author of truth. Like the rich young ruler, there comes a point when the boundary line may be reached and the heart is set permanently against the truth.
Daily we are making decisions that either harden the heart or soften it. What softens the heart? Receiving the grace of Christ. When we behold Jesus with a desire to serve Him, the heart is softened. When we reject truth, it becomes easier to reject it again. Thus, we are deciding our future each day. The mind gradually adapts itself to what it is accustomed to behold. By beholding we are being changed. It is both a spiritual and an intellectual truth. "But we all, with open face beholding as in a glass the glory of the Lord, are changed into the same image from glory to glory, [even] as by the Spirit of the Lord." 2 Cor. 3:18.
If the heart can no longer be reached, then God will cease attempting to reach it with His grace. His angels will be directed to leave the one joined to that which they love more than Christ and His truth.
All who become connected with the cause of God will have opportunity to know what is in their hearts. If they prize anything higher than the truth, their hearts are not prepared to receive Jesus, and he is consequently shut out. If individuals, when tested, refuse to sacrifice their idols, and overcome selfishness, pride, and evil passions, it will be said of them as of Ephraim of old, They are joined to their idols, let them alone; and the Spirit of God will leave them with their sinful traits unsubdued, to the control of evil angels. Review and Herald, April 8, 1880.