Brethren..never charge interest to your fellow Christians...it is totally sin...the bible prohibited it strictly...of course we can charge interest to non christians so that to keep make our businesses alive, but never charge to our fellow Christian..consider you charge interest to your mother or father...how do you feel?...obviously you must be feeling bad for that act...so to your fellow Christians... so IS IT SIN TO CHARGE INTEREST?...The simple answer is YES. God Bless