god is sovereign in the affairs of his creation (and i do), your so-called "chance meeting" is in fact a divine appointment god has been arranging for hours, days, or even years. the blessing of a life or the salvation of a human soul may be what god wants to place on your "to do list," and, if you fail to understand that possibility, you may miss an appointment god has made for you.
god may have arranged for the path of one who has forgotten him to cross your path so that you can do some reminding about grace. he may have brought a hurting heart before you, so you 