Every Humanist must show everybody who will listen that Humanism is true. Some may prefer to spread the word anonymously and in secret and that is fine but everybody has to do something. Always start by getting others to see that they should listen to points of view that they do not share and that they should think.
Any religion that does not give its adherents the ability to check it out responsibly is a fraud. If it is the right religion it is acting as a fraud would act.
It is most important that people know where they can get information when they want it. Works that refute all religious errors must be available to everybody in every area or they must know where they can find such information through advertising and posters. Never forget that our job is to persuade people to think for themselves - nothing more and nothing less. The Gospel According to Atheism must be put in every pair of hands and distributed freely and be available in every public library.
Simple, short and straightforward and polite tracts which should be distributed from door to door or mailed are the secret to defeating religion. That is the preferred method of reaching people for it is less intrusive.
To devote the most time and attention to the most knowledgeable lapsed religionists and share Humanism with the clergy and any who put themselves forward for the ministry is preferable. Make sure you know what they believe or what their Church believes and concentrate on the foundational issues, their main doctrines, one of which will usually be the existence of a loving creator, only and never attack but engage in a gentle and understanding conversation and let the other person talk.
We do not want everybody to join an organisation called Humanism though we hope that it will happen for it is the ideal - everybody has to do what is right for themselves - but to change their thinking and to get people who are willing to make sure the message of Humanism will be spread.
Humanists must not be pompous or denigrate those who obey reason as they see it and who may believe in free will and a God and judgement as long as they do their best to be rational. For example, we must cooperate with people like Deists who believe in God but not in revelation. We must not antagonise but try to learn from one another. We must be realistic and remember that it will often be the case that nothing more can be done than to instil in people a sincere and open reverence for reason. Once that is instilled a lot can be done to counteract the deadly influence of unreasonableness.