I lose interest in most of the things sooner or later, including paths I explored, and deities/entities I worked with - I tend to return to them eventually, as it's completely fine to me to do so -, but in most cases I rather take it as 'something else is calling, and I listen', and not as a 'failure' or a loss of 'faith' I'd need to cope with. Perhaps because my true faith lies within myself, and what I've built and solidified through my experiences, or sole intuition that always guided me and had my trust.
It's not a sin nor an issue when you have the urge, the intuition, the calling to seek out new things or lack interest in one you had before. It's a sign your soul is craving to seek for more, whether within that belief system you followed, or it is an attempt to show you there's more than what you are firmly focusing on, and you may have just missed it.
It is not a loss for me. If anything, it is a chance to learn something else other than what previously did interest me, and what was not interest me beforehand. I don't follow a specific 'belief' system, which may help me not think of these turns as a 'betrayal' of it, or failing; as I was always following my feelings, intuition, therefore I haven't failed myself, which is the most important wherever you go, whatever you practice, whoever you contact.
Briefly back to belief systems, I always had my own, and it just further developed through my years of wandering. I never took 'taking another turn' as a loss or something negative, because all of the walked paths has been a part of me, and helped me to form what I believe and how I understand things.
Change is natural, and it's a part of our learning, exploring, understanding and drawing conclusions.
Sometimes, even people will try to make you feel like you commit a crime, a sin by 'going on a different path', but you really should not allow that to happen. The only thing 'obvious' in your life is you.
How many times I felt like 'finally, I found where my place is', and then it just became one of the many way station for swallowing knowledge, experience, inspiration, finding answers, just to proceed. I learned not to see these as 'permanent'; I learned to respect these, and take the most they could give to me.