I do not think the teaching of "not judging" is suitable to answer this question.
"Not judging by use of Gods Laws" is a better summation for:
Galatians 5:4
You are severed from Christ, you who would be justified by the law; you have fallen away from grace.
This would be for those who are persecuted and abandon faith:
Mark 4:17
And they have no root in themselves, but endure for a while; then, when tribulation or persecution arises on account of the word, immediately they fall away.
Hebrews 10:39 But we are not of those who shrink back and are destroyed, but of those who have faith and preserve their souls.
This says such falling away is permanent:
Hebrews 6:4-6
For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, and have tasted the goodness of the word of God and the powers of the age to come, and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt.
This says that faithful believers can repair their lack of love in faith:
Revelation 2:4-5
But I have this against you, that you have abandoned the love you had at first. Remember therefore from where you have fallen; repent, and do the works you did at first. If not, I will come to you and remove your lampstand from its place, unless you repent.
This says "the proud" are in trouble. I consider these who judge others as the "proud" becasue they hold others lower than themselves due to their vile sins:
Romans 11:19-22
Then you will say, “Branches were broken off so that I might be grafted in.” That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear. For if God did not spare the natural branches, neither will he spare you. Note then the kindness and the severity of God: severity toward those who have fallen, but God's kindness to you, provided you continue in his kindness. Otherwise you too will be cut off.
Matthew 24:10-13
And then many will fall away and betray one another and hate one another. And many false prophets will arise and lead many astray. And because lawlessness will be increased, the love of many will grow cold. But the one who endures to the end will be saved.
2 Peter 1:5-10
For this very reason, make every effort to supplement your faith with virtue, and virtue with knowledge, and knowledge with self-control, and self-control with steadfastness, and steadfastness with godliness, and godliness with brotherly affection, and brotherly affection with love. For if these qualities are yours and are increasing, they keep you from being ineffective or unfruitful in the knowledge of our Lord Jesus Christ. For whoever lacks these qualities is so nearsighted that he is blind, having forgotten that he was cleansed from his former sins.
I see two groups, the proud who judge others by the law, then die by the law they claim to be keeping and those who abandon faith when times are tough.
The first is leaning toward the law, but can be brought back to love under grace.
The first group is deluded that the law saves, but they still believe in God but have not yet accepted Grace from the condemnation of law, under Jesus.
Heresy warning! I think all other religions are in this first group and have the opportunity to learn about grace under Jesus. They believe in God above us, but are missing the details about Jesus saving us from death under the law.
The second group is lost permanently due to lack of faith in God altogether. We can still voice our love and concern but God will decide their final fate.