It is a great virtue to take in guests. On Pesach, it is even greater obligation than usual. One gains two things by inviting guests. First, he is able to recite the Haggadah, the Hallel, and Birkas Hamazon with a group, which is always better than solitary prayer. Besides this, one helps the guest observe the Seder properly. If a person is alone away from home it is difficult for him to do everything as he should. Helping another fulfill a mitzva brings great reward in the next world. If one has the opportunity to the Seder, but refrains from doing so, he is like a liar. At the Seder he says, "Let all who are hungry come and eat." Yet, he had the opportunity to invite a guest, and he neglected to do so.
(Me'am Lo'ez)