That’s true, but we still need remind ourselves that should not judge, or judge a book by its cover by outward appearances for some God could be, or is working on someone’s heart.
The prodigal son is the perfect example of this.
Can a true born again believer in Christ still have rebellion in their heart ?
The answer is yes, they may not be going to hell for it, but they sure will get a spanking from it, God’s chastisement as their father.
Those whom he loves he chastises.
I am not sure the prodigal son is an example of a wayward Christian. I would need to restudy that to decide what I think on that specifically.
True Christians will stumble. They don’t fully reject everything.
As for judging, we cannot send anyone to hell. God is the judge. We are not to be vengeful; vengeance is God’s. But we are told we will “know them by their fruits.” That we should “gently and humbly” help those who go astray. That we should be discerning regarding false teachings/teachers. That we should not keep company with wayward professors of faith. That we should follow church discipline for sinning brothers/sisters — kick them out, though with the aim that it will lead them to repentance. In that sense there is judgment. We are to examine our own hearts. That is judgment. And in sharing the Gospel of God with its call to repentance, there is judgment. It is not that we are the judge. But we are proclaiming the judgement of God when we proclaim the good news of His grace.
As Jesus said, “Unless you repent, you will likewise perish.”