I hate to disagree with Dr. Just, but I don't think heaven comes to earth on Sunday morning. Nor do I think departed Christians are present during Communion. Hebrews talks about Mt. Zion and Mt. Sinai, but I think it is saying we are forgiven by the Gospel instead of being condemned by the Law. Actually being in heaven is something we have to die to experience. Communion is a foretaste, not the feast to come. And the reference to "all the company of heaven" is from a (not divinely inspired) prayer that simply says we praise God in the same way that angels and saints praise him in heaven. And Luther said in the Large Catechism that the "communion" of saints means that the Church is a community, not that there is some mystical link between the living and the dead. The Lord's Supper gives us Christ's body & blood, along with forgiveness, life, and salvation--here on earth. The liturgy does not join heaven and earth except in a metaphorical sense. Christ blesses us with the Word and sacraments, but we are still on earth, not in heaven. Just my two cents.