Ari Sytner, Orthodox, Author of “The Kidney Donor’s Journey”: Judaism is a purpose. We exist as a means to something greater than ourselves. The mandate that the Almighty has given us, is to be a “light unto the nations,” which empowers us to spread Godliness wherever we go. The need for Tikkun Olam, repairing a broken world, is perhaps more evident today than ever before. The way in which we carry out this purpose is not merely in rhetoric, but by walking the walk and proudly demonstrating to our children, communities, and the world around us, a fidelity to the traditions of our ancestors. We achieve our purpose in the world, not by knocking on doors and trying to convince others to adopt our way of life, but by studying, practicing, and humbly modeling the values of Torah. When we look around us and see those demonstrating incredible acts of philanthropy and kindness, it becomes a symbol of what Jews are really about — and by extension, what God is about.
Read more: https://forward.com/opinion/spirituality/389736/we-asked-23-rabbis-what-are-jews-exactly/
(ט) ישראל מומר שקידש קדושיו קדושין גמורים וצריכה ממנו גט ואפילו זרעו שהוליד משהמיר אם קידש אותו זרע ישראלית קדושיו קדושין ודוקא שהולידו מישראלית אפילו מומרת אבל אם הולידו מן הכותית דינו ככותי אפילו היה המוליד ישראל שאינו מומר אבל ישראלית מומרת שיש לה זרע עם הכותי שקידש קדושיו קדושין (מרדכי סוף החולץ):
(9) If a Jewish apostate betrothed [a Jewish woman] his betrothal is completely valid, and she requires a writ of divorce. Even if he had children after he left Judaism, if one of those children were to betroth a Jewess, the betrothal is valid. This is only true if he had children with a Jewess, even if she is an apostate. If, however, he had children with a non-Jewess, the children are considered non-Jews, even if the father is a Jew who is not an apostate. Rem"a: If a Jewess apostate had a child with a non-Jew, that child's betrothal is valid.