Complex sentence: Jewish Christians are not considered bona-fide Jews under Israel's Law of Return, there are an estimated 10,000 adherents in the State of Israel, both Jews and other non-Arab Israelis, many of whom are expatriates or immigrants from the former Soviet Union.
Split into simpler sentences: Jewish Christians are not considered bona-fide Jews under Israel's Law of Return. There are an estimated 10,000 adherents in the State of Israel, both Jews and other non-Arab Israelis, many of whom are expatriates or immigrants from the former Soviet Union.