Just as there are tall people in short families (none of the other men in Michael Jordan’s family was over 6 feet tall), there are religions that deny the existence of God and religions that get along just fine without creeds. Something is a religion when it shares enough of this DNA to belong to the family of religions. What makes the members of this family different (and themselves) is how they mix and match these dimensions. Experience is central in Daoism and Buddhism. Hinduism and Judaism emphasize the narrative dimension. The ethical dimension is crucial in Confucianism. The Islamic and Yoruba traditions are to a great extent about ritual. And doctrine is particularly important to Christians.
There is a long tradition of Christian thinkers who assume that salvation is the goal of all religions and then argue that only Christians can achieve this goal. Philosopher of religion Huston Smith, who grew up in China as a child of Methodist missionaries, rejected this argument but not its guiding assumption. “To claim salvation as the monopoly of any one religion,” he wrote, “is like claiming that God can be found in this room and not the next.” It might seem to be an admirable act of empathy to assert that Confucians and Buddhists can be saved. But this statement is confused to the core, since salvation is not something that either Confucians or Buddhists seek. Salvation is a Christian goal, and when Christians speak of it, they are speaking of being saved from sin. But Confucians and Buddhists do not believe in sin, so it makes no sense for them to try to be saved from it. And while Muslims and Jews do speak of sin of a sort, neither Islam nor Judaism describes salvation from sin as its aim.