Hazrat Moulana Muhammad Ilyaas (rahmatullahi ‘alaih) once mentioned:
The primary purpose of the effort of Da’wat and Tableegh is to turn people away from the wrongs that Shaitaan invites them towards and bring them to the complete obedience of Allah Ta‘ala. However, without effort and sacrifice, it will not be possible to achieve this purpose. Hence, to achieve this goal, people will be required to sacrifice their lives as well as their wealth for the cause of Deen.
In the case of Da’wat and Tableegh, sacrificing one’s life refers to one leaving his home and going out in the path of Allah Ta‘ala to spread the message of Allah Ta‘ala and propagate Deen, and sacrificing one’s wealth refers to one bearing his own expenses and using his own money to go out in the path of Allah Ta‘ala. (Malfoozaat Hazrat Moulana Muhammad Ilyaas (rahmatullahi ‘alaih) pg. 36)