Despite all the quoting of Deuteronomy 7:3,4, Israelites could marry non-Israelites. Ruth was married by an Israelite man although she was a Moabite. Esther, an Israelite woman, married a Persian king.
Ah... but they didn't give up their faith. Inter-faith marriages were born.
and I'm not sure you argue Ruth, as doesn't appear she converted until she was left a widow.