It's important to clarify that not all atheists necessarily believe that "literally everything is a sin." The concept of sin is rooted in religious and moral frameworks that typically involve the belief in a higher power, like God, who sets the rules or standards for human behavior.
Atheism, by definition, is the absence of belief in gods or deities. Atheists may base their moral values and ethical principles on secular humanism, rationality, empathy, societal norms, and a sense of compassion and well-being for themselves and others. They don't necessarily have a religious framework of sin or a divine lawgiver that designates certain actions as sinful.
The idea of sin varies among different religions and belief systems, and what constitutes a sin in one faith may not be regarded as such in another. For atheists, moral and ethical considerations are often based on a naturalistic perspective and a concern for the well-being and happiness of individuals and society as a whole.
It's essential to remember that ethical discussions and moral frameworks are complex and diverse, involving input from various philosophical, cultural, and individual perspectives. Atheists, like people of any belief system, can have a wide range of views on morality and what constitutes appropriate or inappropriate behavior, but their views are not typically framed in the context of "sin."