Consistent effort in your healing process provides the best results. Past life healing therapy is the perfect aid to meditation/self-discovery, irrespective of your religion / faith / beliefs / scepticism.
It does not matter whether you believe the experiences of a past life healing session are an actual past life memory, or just imagination, or merely symbolic. Try to approach a session with child-like innocence and suspend what you think you already know. If you remain open and non-judgmental then you can allow the healing to occur. If you allow the analytical /rational/conscious side of your brain to dominate then you will miss the opportunity (and, in any event, you will have plenty of time to analyse your experience after the healing session has concluded). So empty your mind and trust in the process to get the best results out of a session.