We all have faced this problem with somebody we know or Love. I have been surrounded by those my entire life who are fighting the demons of addiction, to the point i am now fanatical against it. All I will say on the subject, is that yes it is between you and God, and it is your personal battle. But it affects everyone who is near you.
O Divine Providence! Bestow Thou in all things purity and cleanliness upon the people of Bahá. Grant that they be freed from all defilement, and released from all addictions. Save them from committing any repugnant act, unbind them from the chains of every evil habit, that they may live pure and free, wholesome and cleanly, worthy to serve at Thy Sacred Threshold and fit to be related to their Lord. Deliver them from intoxicating drinks and tobacco, save them, rescue them, from this opium that bringeth on madness, suffer them to enjoy the sweet savors of holiness, that they may drink deep of the mystic cup of heavenly love and know the rapture of being drawn ever closer unto the Realm of the All-Glorious. For it is even as Thou hast said: “All that thou hast in thy cellar will not appease the thirst of my love—bring me, O cupbearer, of the wine of the spirit a cup as full as the sea!”
Selections from the Writings of Abdu’l-Bahá, 129.12