Becoming a counsellor or a psychotherapist requires a high level of self-awareness, genuineness, congruence and empathy. Having a certain number of hours of personal therapy is required to complete the training program and achieve accreditation.
Therapists can hope to gain several things by having their own therapy:
Appreciate the reactions and needs of clients by being placed into the client role,
Understand the process of therapy itself
Develop self-awareness (which can prevent unhelpful interventions being made)
Build up the habit of self-reflection
Become aware of transference and countertransference in the therapeutic relationship
Experience gains made in therapy