The United Church of Christ, one of the nation's most liberal Christian denominations, accused CBS and NBC yesterday of rejecting a commercial it had produced about religious tolerance, which included an implication that other denominations did not welcome gays, because the networks feared hostile reactions from conservative political and religious groups. The networks said they turned down the commercial for the same reason they had rejected numerous issue-oriented commercials in the past: they do not allow advocacy advertising. Network executives also said that the church might have been more interested in gaining publicity. Both networks said they had accepted a...