May one invite a guest for Shabbat dinner knowing that he will violate Shabbat either coming or going to our house? The Torah states, "You shall not place a stumbling block before the blind" (Vayikra 19). The Talmud interprets this verse that we may not cause another Jew to sin through our actions.

Thus, Rabbi Shmuel Wosner (Shevet HaLevi 8) and Rav Yosef Shalom Elyashiv both rule that such Shabbat invitations transgress this prohibition, of causing a Jew to violate the Shabbat, through my invitation. Rav Moshe Feinstein (Igrot Moshe 1) agrees, and even says that inviting a Shabbat violator to you home on Shabbat also involves the prohibition of inciting sinful behavior (MESIT), (Devarim 13).
However, my Rosh Yeshiva Rav Yakov Kaminetsky (Emet LeYakov 423) and Rav Shlomo Zalman Auerbach (Minchat Shlomo 2) rule that one may phrase the Shabbat invitation in such a manner that would not automatically lead to a Shabbat violation.

Thus, one may invite guests for the entire Shabbat, and even if they are unlikely to stay that long, you may encourage them to come for a Friday night meal, arriving before Shabbat begins, even if they will drive home later. Rabbi Moshe Sternbuch allows even Shabbat day invitations to Shabbat violators, because he believes Jews do not violate the LIFNEI IVER prohibition of placing a stumbling block before the blind, because our intention is to bring other Jews closer to Judaism. When the Shabbat violator sees the beauty of our Shabbat table, with inspiring Divrei Torah and beautiful z'mirot, it may ignite his PINTELE YID to embrace Torah true Judaism, as the song says "Light My Fire".
This lenient approach is used by CHABAD throughout the world, and has brought many thousands of lost Jews back to their Torah roots and G-D's loving embrace.