the question concerning: When is it appropriate to share your religious faith with others? Is a good question, allow me to establish how I feel concerning the options given and than give you my own suggestion to the question.
-Knocking on doors
No, that's in all ways the most arrogant thing you could do. The way I see it is that: Knocking on someone else door represents urgency + A Religious Message = "My Religion is so important that I believe it is the only way to save you!"
Its a sacrilege against God. Typically opening your door to a stranger, I think of a salesman trying to sell you something. I wouldn't do it. Religion is not meant to "be sold"
-Passing out written materials
Like what, the central spiritual texts? Or like information about said religious group? If it is the latter than I see no harm, especially if a particular religion has a stigma in a particular society it would be best to correct misunderstandings.
-Inviting friends to religious services
Only if my friends are open to the idea...
-Telling friends about your beliefs, with or without invitation
No, only in an invitation would I discuss and I would try to be unbiased as possible.
-Mission trips to share beliefs and do good works
I don't see whats wrong with this, after all I believe that if you want to get people into your religion you should not have to sell it but lead by example. Doing good works is leading by example and this is probably the best option out there.
-Faith-based movements or attempts to change laws or politics, from the Puritans to Dr. Martin Luther King to pro-life groups
These have a worldly agenda, keep your religion to thyself if we are to do any change it should be to take a libertarian approach (The right to do what you want to do; without imposing your ideologies among others). So I am pro-life, if their is someone pro-choice I'm not going to fight them and demonize their ideologies instead I will just say it is my personal choice.
-Sharing beliefs with someone who is in distress
Only if in their distress they ask for what I believe or have come to understand...
-Faith-based help projects such as homeless shelters that require text studies, hospitals with religious ministries to patients, drug treatment programs (e.g., Scientology's Narconon), etc.
I don't see whats wrong with this, after all I believe that if you want to get people into your religion you should not have to sell it but lead by example. Doing good works is leading by example and this is probably the best option out there.
-Pointing out weaknesses or faults in someone else's beliefs
Never, that is the most arrogant thing you can do, unless its constructive and ONLY IF they welcome it.
-"Slacktivist Witnessing" - e.g., holding up signs at football games, religious graffiti, T-shirts, etc.
No not my thing... It implies things to me, that their beliefs are right and mine are wrong some how. Its like knocking on the door.
-Other??
Yes here is my own suggestion, to the question "When is it appropriate to share your religious faith with others?" How about when you understand the religious faith you uphold? When you say "Its not for everyone and I know this." It is when you have actually understood your religious convictions when you should share them. When I say understand I dont mean in the superficial sense either, Im talking a deep understanding.