I do not judge who is christian or not, and i believe that is one of the teachings in the bible. Matthew 7:1
They come in all shapes and sizes, they come from the worst of people to the best of people. One thing ties them together, they are Christian.
Yes, 'judge Not according to appearance' according to Jesus at John 7:24 and see Luke 7:33-34.
Remember the 'woman' at Luke 7:37 she was a known sinner so the reputation was already known about her.
So, at Matthew 7 Jesus was speaking about ' personal ' judgement of another, Not judging God's judgement.
Thus, Jesus' Sermon on the Mount is an appeal to us to have his teaching principles to govern our lives.
Living principles that the world is now much void of such righteous principles of morality and behavior.
If we continue reading in chapter 7 we find at verse 20 a genuine 'wheat' Christian would be known by fruit.
Remember the old adage that one rotten apple can spoil the whole bunch.- Matthew 7:19
Fake 'weed/tares' are the figurative rotten apples, but they do Not spoil the 'genuine' whole bunch - Matthew 7:14-16
Jesus' New commandment found at John 13:34-35 gives us a clue as to who is a real /genuine Christian.