Within Catholic Christian community, antisemitism and supersessionism comes from both the Modernist camp, that rejects the promises of the land of Israel God made to Abraham, and the traditionalist camp, which rejects the role of Jews in the Church in the Second Covenant. I believe the most important contribution I can make to the community, as a Catholic convert from Judaism, is explaining the continuity between the Old and New Covenant in traditions and beliefs to those around me. For example, I veil in front of the Blessed Sacrament and I sometimes get questions about it. There are many different reasons why Christian women might cover their heads in Church, but I like drawing continuity between the practices of some Jewish women of wearing veils when lighting Shabbat candles. Alternatively, I like talking about the similarities between the blessings said during Shabbat and the blessing of the bread and wine before Consecration at Mass.
