Five Main rights of believer to each other

Messenger of Allah (ﷺ) said,
“A believer owes another believer five rights: responding to greetings, visiting him in illness, following his funeral, accepting his invitation, and saying ‘Yarhamuk-Allah (May Allah have mercy on you),’ when he says ‘Al-hamdu lillah (Praise be to Allah)’ after sneezing”.
[Al Bukhari and Muslim]