If they can be made wrong with Him afterwards supposedly, then they were never truly made right with Him to begin with. and the error comes in and with us and our thinking we can tell or judge or know for sure, either in and with ourselves and/or especially with others, or in others cases.
And about the former that i just said, do you not think that God can see a persons end from their beginning? and that if they were or are not His in the end, then they were never one of His or were ever right with Him to begin with? those who are truly His in the beginning or in the end(ing) cannot ever become not one of His after they are truly one of His.
Obedience does not earn you better or more right standing with God, or Salvation either. And/or and because if you see it that way at all, you are already not being obedient, but are being disobedient and not obedient from the heart, because you are not having the right kind of heart to begin with, which is being disobedient. Or not being truly obedient to the true Gospel of Grace apart from works or works of law, which and/or because the latter is disobedience to the True Gospel of Grace.
You will sin in your judging and/or condemning, and judgments and judging in and from your heart, etc, and even if you don't voice it, you will be being disobedient in your thoughts and from the/your heart, if your following after the wrong Gospel.
Works, or works of law and the Gospel of Grace cannot co-exist together ever, nor can they be "mixed" either, it's one or the other and you must choose and do it in and from your heart.
True obedience is in having the right kind of heart, and if you do not have the right kind of heart, then you are still stuck in the/your sin and disobedience. And pure works based "whatever" does not ever, never, nor can it ever give you the right kind of heart, or ever produce a person that is ever truly obedient from his or her heart, ever.
God Bless!