Final answer:
The interest of the church is that of a Life estate pur autre vie.
Step-by-step explanation:
The interest of the church in this situation is that of a Life estate pur autre vie. A life estate pur autre vie is a type of estate where the duration of the estate is based on the life of someone other than the holder. In this case, Mr. and Mrs. Jones retained the right to occupy the property as long as they lived, meaning their interest in the property is based on their lives.