I think I will be approaching this verse from a slightly different angle than we are used to.
A few days ago, certain events got me thinking about how wrong or inappropriate it is to refuse correction or wise counsel from someone just because we think the person kids or friends or siblings do not behave well.
Let me give an example:
Person A: I think you should try doing this, you know the Bible says…..
Person B: you should teach that to your kids or how can you advice me when your own kids do not……
How wrong! How inappropriate! I have often been caught in this ungodly behaviour but you know something? A person does not have to be obeyed or respected by his family to be used by God. God doesn’t work based on human sentiments. The fact that that friends and family do not respect a person’s Christian work or faith doesn’t mean you cannot take that person seriously when it comes to the things of God.
If there are certain preachers you refuse to take seriously simply because the behaviours of their children do not reflect the scripture then you may be judging too quickly. Understand that your leaders in church are not perfect and often times, the devil tries to get at them through their families.
My advice would be to pray for them rather than write them off.