We can all serve in the Cause of God no matter what our occupation is. No occupation can prevent the soul coming to God. Peter was a fisherman, yet he accomplished most wonderful things; but the heart must be turned always toward God, no matter what the work is; this is the important thing; and then the power of God will work in us. We are like a piece of iron in the midst of the fire which becomes heated to such a degree that it partakes of the nature of the fire and gives out the same effect to all it touches -- so is the soul that is always turned towards God, and filled with the spirit.
(‘Abdu’l-Baha’s remarks to a group of pilgrims, 1899; ‘An Early Pilgrimage’, by May Maxwell)