From Epistles – Third Series of Volume 7 of The Complete Works of Swami Vivekananda (Translated from Bengali)
MY DEAR GUPTA (Swami Sadananda),
I hope you are doing well. Do your own spiritual exercises, and knowing yourself to be the humblest servant of all, serve them. Those with whom you are staying are such that even I am not worthy to call myself their humblest servant and take the dust of their feet. Knowing this, serve them and have devotion for them. Don’t be angry even if they abuse or even hurt you grievously. Never mix with women. Try to be hardy little by little, and gradually accustom yourself to maintaining the body out of the proceeds of begging. Whoever takes the name of Ramakrishna, know him to be your Guru. Everyone can play the role of a master, but it is very difficult to be a servant. Specially you should follow Shashi. Know it for certain that without steady devotion for the Guru and unflinching patience and perseverance, nothing is to be achieved. You must have strict morality. Deviate an inch from this, and you are gone forever.