In my opinion, the best way that you can benefit your family is by commiting yourself to progressing as much as possible. In the early stages of the path, your progress won’t be very noticeable (if at all) to others. However, as you continue to progress, people who know you well will start to pick up on the fact that you are calmer and have fewer desires. They can subsequently be more inclined to listen to what you have to say. No guarantees though.
A Quest to Recover Buddha's True Teachings
