תלמוד על אבות 3:15

Rabbi Shimon ben Elazar would say: When the people of Israel are in foreign lands, they worship idolatry without meaning to. How so? A Samaritan makes a party for his son. He sends out an invitation to all the Jews in his city. Even though they eat and drink their own food, and bring their own attendants who stand and pour for them, it is still considered as if they ate from the sacrifices of the dead, as it says (Exodus 34:15), “They will call to you, and you will eat their sacrifices.”
Rabbi Eliezer HaModa’i would say: Anyone who violates the Sabbath, scorns the festivals, disregards circumcision, or attempts to reveal the flaws of the Torah, even though he may be learned in Torah and have done many good deeds, he has no share in the World to Come.
Rabbi Akiva would say: Anyone who marries a woman who is not proper for him transgresses five commandments: “Do not take vengeance” (Leviticus 19:18), “Do not bear a grudge” (ibid.), “Do not hate your brother in your heart” (Leviticus 19:17), “Love your fellow as yourself” (Leviticus 19:18), and “Let your brother live with you” (Leviticus 25:36). Because he will hate her he will want her to die, and this will cause fewer children to be born into the world.