I’d say “No in general, but perhaps yes in specific cases, depending on circumstances”.
Most cultures, even those that are largely secular, recognize that humans have a potential for both good and evil. This has been explained in various ways - biological (we act on evolution-derives urges such as predation and sexual drive), supernatural (the world is divided between good and evil beings / gods), or environmental (the way we are brought up determines whether we turn out good or evil.)
The Christian answer to this age-old question is that we are made in the image of God (and are therefore “good”) but that we also inherit the consequences of the Fall, namely original sin and a tendency towards further sin later in life (and are therefore “sinful”). We do not necessarily define ourselves exclusively as “sinners” first and last. (There are some strains of Reformed thought, particularly Calvinism, that insist on “total depravity”, however, Calvinism was constructed by a lawyer, and is certainly rejected by the majority of the world’s Christians), but we recognize our sinful nature and try to keep it in check, by seeking and cooperating with grace of God.
Now, this could theoretically lead to problems (scrupulosity, depression, etc.) in certain vulnerable people, but by and large, I think having a sense of our own limitations (and in the end, sin is a reminder of human imperfection and limitation) is a healthy rather than an unhealthy thing. Moreover, when we are tempted to pass judgment on X for sin Y, realizing that we could easily have done Y (or the similar Z) ourselves can also help us avoid self-righteousness.