39 The material necessities which affect the faithful also affect the life and structure of the Church. It is therefore necessary that native Christians become accustomed to supporting, spontaneously and within the limits of their means, their churches, institutions, and clergy, who are entirely devoting themselves to them. It does not matter whether they can give much, but it is of the greatest importance that what is contributed is proof of a conscience that is practicing Christian discipline.
Source: Princeps Pastorum (Vatican.va)