Because the sealing is performed in the Latter Day Saint Temple only those who have Temple recommends are able to attend. Those are given to members of the Church of Jesus Christ of Latter Day Saints when they meet with their Bishop (Pastor) and are deemed worthy to enter the Lords house.
This is a Latter Day Saint ordinance where the bride and groom are married or sealed together by the priesthood authority of God in the Temple. They are sealed together by the priesthood which transcends time and death. It is an eternal marriage.
We will provide light refreshments and snacks but we would advise those who want a full meal to eat something before attending the reception. We will have cake, fruit, veggies and other desserts.