As a marriage progresses through the years, with all the ups and downs that that entails, a reaffirming of a couple's commitment to each other, especially after such life changing events such as the children leaving home, can be a very beautiful way of reconnecting to each other.
Older and wiser, an Interfaith ceremony would be a public or private way of celebrating how your love for one another has transcenced anything that life may have thrown at you both.
A redeclaring of a version of your original wedding vows could touch the place inside you both of your original attraction to each other, and this can be very touching for your children, family and friends to witness. The ceremony would not only honour yourselves as individuals but also your joint achievements. It could be built around themes that have especial significance in your lives yet also look forward to how you would like the future to be for both of you, a way of together saying "Yes" to whatever is to come.