Which critical issue can be described as being fundamental to the success of a therapeutic group that authenticity prevail and that members do not feel they have to disguise or hide their true selves to be accepted?

Authenticity vs. Guardedness

Explanation:

It should be understood that authenticity is the quality of being genuine or not corrupted from the original, that is , the act of always being real you.

The major thing that describes you of being authentic is to be honest in every aspect. For example, you should be honest in your workplace, be honest about the skills and experience you possess.

It should be noted and understood that they benefit of being honest will make people to trust and respect you.