How do you determine what is right, when all options are on the table? The question is always: what benefits the most?
Often, what benefits the most is not trivial to calculate. Without other information, that which you least want to do is usually what you ought to do. But not always.
Benefit must be measured in more than normal terms. It isn't just about the greatest quantity of benefit. Sometimes, the worth of something is in its rarity.
For example, suppose you are evaluating whether to keep associating with a group of people: your church, your friends, your family, etc.
Maybe it isn't the the quantity of teachings God is sending from you to them that are of the most worth. Maybe it is the fact that you are the only one willing to suffer what is required to endure to get it to them. Maybe your willingness to suffer beyond what others would is producing fruit in this individual that could be had in no other way. No matter how infinitesimally small or glacially slow, the rarity of the fruit in them may be more valuable than the quantity you and many others could produce in someone else.
This perspective can be taken too far if it isn't jointly evaluated with the good you would otherwise do for others if you were in a different situation. Perhaps there is even greater value in something else you could do.
Also, don't use longsuffering as an excuse to persist in an unfruitful situation. Slow fruit or small fruit is not the same as no fruit. Jesus lamented the slow fruit of his disciples, bemoaning how long he needed to suffer them, but he cursed the fruitless fig tree. When evaluating the wisdom of persisting in attempting to help someone, ask if they have changed at all? If they have, do they continue to? If not, leave.
Paul is a good example of navigating the diversity of persistence options. He stayed with some a long time, others a short time, and some he left without ever attempting to preach. If you want to learn more about this topic, maybe Acts + Paul's letters are a good place to study.
Always ask if this is the most good you can do. Doing good is not enough. You must do what is best.