Prior research on those who are “not religious” in the traditional, organizational sense has focused on a broad category of people in the United States who do not identify with an established religious tradition. We distinguish three categories of people who are religiously nonbelieving or nonbelonging: atheists, agnostics, and unchurched believers. Examining issues of religious belief and identity, we compare private spiritual life, attitudes on political issues, and stance toward religion in the public sphere for these three categories of nonreligious respondents. Atheists are the most uniformly antireligious. Agnostics, by comparison, are less opposed to religion overall, while unchurched believers display higher levels of personal religiosity and spirituality than atheists or agnostics. While atheists, agnostics, and unchurched believers are similar in their political identification and attitudes related to religiously infused political topics, unchurched believers are as strongly opposed to religion in the public sphere as atheists.