What is the ruling on da'wah (inviting others to Islam)?

The call to Allah (Da'wah) is an obligation upon the Ummah (Muslim community) as a collective duty (fard kifayah), and it is an individual obligation (fard ayn) upon every Muslim according to their ability and knowledge, based on the Prophet’s (peace be upon him) saying: "Convey from me, even if it is a single verse." Interpreters (Mufassirun) differed on the meaning of "min kum" (from among you) in the verse: "And let there be [arising] from among you a nation inviting to [all that is] good," whether it signifies partiality (which is the more preponderant view) or denotes genus. A reconciliation between the two views is possible: the establishment of a group dedicated to Da'wah is a collective obligation (fard kifayah), while every individual's engagement in Da'wah according to their capacity is an individual obligation (fard ayn), based on the verse: "And why should not some party from every division of them [go forth to] obtain understanding in religion and warn their people when they return to them?" Thus, Da'wah is obligatory for every individual according to their capacity, as indicated by the hadith (definition): "Whoever among you sees an evil, let him change it."