Receiving the Father

Catholics, Eastern Orthodox, Seventh Day churches, some Baptists, some Calvinists and others all claim to be the one true church. How should we treat people of other denominations? Would God call it a sin to exclude those who receive Jesus from sharing in a common communion? What would Jesus say about this? In Matthew 10:40 He said, “he who receives Me receives Him who sent Me.” Why would we not receive anyone who receives Jesus and our heavenly Father? If we receive those who receive Jesus, we receive our Father in heaven. Can we receive each other as fellow believers of the important things and not divide over lesser issues?