Salat Behind Shia Or Ahmadia Imam
No, if somebody worships an idol and says he is Muslim. No one will accept it. If a Hindu says to you that he is Muslim and continues to pray his gods and goddesses, no one will accept he is Muslim. Similarly if one doesn’t believe in finality of prophethood of Muhammad SAW, and believes in another prophet then he cannot be called Muslim. As Muslims believe in Christ but no Christian will accept that a Muslim is Christian. Muslim believe in Moses but no Jews will accept that Muslims are Jews. This is a simple rule.