Grellet was born in Limoges, France. At the age
of 23 he became a convinced Quaker after
reading William Penn and George Fox's works, and understanding Quaker beliefs. He became a missionary in Europe and North America, concerned in particular with prison
and education reform.
“I expect to pass through this world
but once. Any good thing, therefore,
that I can do or any kindness I can show
to any fellow human being
let me do it now.
Let me not defer nor neglect it,
for I shall not pass this way again.”