There are individuals certified as officiants through non-denominational congregations who personally have no faith and non-personal theistic groups (Diest, Unitarian) who can perform non-religious ceremonies.
It is better to be religius in case you find a non-religious officiant you can discuss with that particular person to be religious and try to explain him. Or else you must have friends to know about your non-religious officiant so that they can be of some witness to you.
