A Christian who marries an unbeliever is not exemplary and lacks real appreciation for God’s gift of marriage.
was given independent of any religious affiliations (Genesis 2:22) and had nothing to do with a real or imagined appreciation. A gift is defined as something that is bestowed voluntarily and without compensation.
"This gift and blessing of marriage is also an evidence of God’s impartiality and of his justice. How so? In that these joys of marriage, when God is in it, do not depend upon such mundane things as material wealth, a higher education, great physical strength or beauty of form and feature. Neither are marital blessings limited to any race or nationality, nor are they dependent upon any climate. Whether couples live in the polar regions or in the tropics makes no difference."
w81 7/1 pp. 12-13 par. 4 / Let God Be in Your Marriage
Also, their belief system is that successful marriages and united families are only achieved by pecking order:
“Family comes from L[atin] familia, orig[inally] the servants and slaves of a great house, then the house itself with master, mistress, children—and the staff.” — Origins — A Short Etymological Dictionary of Modern English, by Eric Partridge.
w93 9/1 p. 15 / The Christian Family Does Things Together