hindus

Respected scholars, as-salamu `alaykum. Can a Muslim family take a Hindu maid to work in their house or invite Hindu, Sikh,or Buddhist person to their house? My mother-in-law says that “she won’t allow any Hindu to come in to the house.” She fears and believes that they will touch places and it will make it unclean, I suppose. Is her point of view the correct one? My husband also started thinking the same thing. Is this right or justified, when Islam calls us to be friendly to everybody? How one can call people to Islam as we all shall try to do, if we start giving the prerogatives to some and be disgusting or ignore the others? What I can do to make them feel friendly towards the unbelievers. Thank you very much.