Doubt is a sign of Spiritual Growth
In many Christian circles doubt is a secret. We hide our doubts the way we hide our sins, never talking about them in public, maybe confessing them if we get the courage, but mostly fearing that if people were to hear about them we'd be shunned. Part of our fear of doubt comes from a misunderstanding of what Faith really is. We think of faith as synonymous with belief, but that's not what faith has ever meant. When we look at the Old Testament faith in Yahweh meant trust that Yahweh would provide or that Yahweh would uphold their promises. Faith has never truly been about being able to say a creed and believe each statement--that only developed under Constantine as a way to maintain control over his populace, but that's another story for another time. A better definition and understanding of faith comes from the theologian Paul Tillich. He defines faith as the state of being ultimately concerned. What does it mean to be ultimately concerned? And what are you ultimately concerned about? To be ultimately concerned means that there's something that is of ultimate importance to you. A simple example would be being ultimately concerned about either going to heaven or hell when one dies. Another more popular example in contemporary secular and spiritual but not religious culture is that of self-actualization--ensuring that one's life allows oneself to live out their fulled essence. Another example could be the parent who's ultimate concern is providing a good life for their children. So, what are you ultimately concerned about?
Once you think of that for the present, consider if it's different from what you've considered of ultimate importance in the past.
Can you remember when you were transitioning from one ultimate concern to another? How was that period of your life? Additionally, can you see how even if the belief (that which was of ultimate concern) changed, you maintained faith (the state of being ultimately concerned)?
So doubt is never about losing our faith, it's about being called to go deeper into the question of what is of ultimate concern to us. And that question, in a well-lived and deeply considered life, will always be evolving and deepening. Doubt then, become the mark of a faithful person, not one who is faithless.