All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Calling people to Islam is an obligation on every pubescent Muslim according to the best of his ability using any means made available to him. The Prophet said: "Convey on my behalf even one verse (from the Quran)." [Al-Bukhari] Going out to spread Islam is something urged. It is a sound opinion to say that it is obligatory for a person to leave his home to call to Allaah when it is an obligation upon him to call people to Allaah. This is in case the person who goes out fulfils his obligation towards his family, like leaving for them what will suffice them in regard to their sustenance and other needs. However, if the person who calls to Islam goes out of his home while being negligent about his obligations and duties, then he is no doubt contradicting what he is calling to.
Allaah Knows best.