The king spake, and said, Is not this great Babylon, that I have built for the house of the kingdom by the might of my power, and for the honour of my majesty?
While the word was in the king's mouth, there fell a voice from heaven, saying, O king Nebuchadnezzar, to thee it is spoken; The kingdom is departed from thee.
The admonition is not to think within our selves, nor to say by our own power, that we have no more sin to fight, and so have no more temptation to endure.
Post-resurrection perfectionism is having no unrighteous, unclean, sinful, or unkind thought whatsoever, so as not even to enter into the mind.
The commandment and law of Christ on earth is not such perfectionism, which is impossible in corruptible natural flesh and bones.
The law of Christ to His saints, is simply not to take thought for them, nor to dwell upon them so as to lust by them after the flesh.
Being pure in heart with Jesus is simply not having lust for sin in the heart, which does not mean having no sinful thought of the devil whatsoever to enter the mind, Those are the fiery darts of the wicked that certainly will come day to day to test the endurance of the saints.
The birds will certainly fly overhead to eat of our sacrifice to Christ, but like Abraham of old, we chase them all away and do not allow them to nest in our souls.
So long as we are alive and remaining on earth, there will be passing thoughts of unrighteousness, Which is not sinning against Christ.
But, Lusting for them to do them with the flesh, that is committing sin already within the heart.
Them who say they have no sin and are deluding themselves, are the perfectionists that are saying they no longer have so much as a thought for sin entering their mind, and so no longer need endure temptation and fight the good fight of purity in the faith.
They act as though the resurrection is passed for them, and in their pride they themselves are cast down from God's presence:
Who concerning the truth have erred, saying that the resurrection is past already; and overthrow the faith of some.
And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit.
Jesus is not a perfectionist in this life, nor is His law one of commanding post-resurrection perfectionism in the mind and spirit of His people on earth.