I don’t know that God exists, nor that Jesus died, was buried, and then rose again. I don’t know that the Bible is the Word of God. Yet, I call myself a Christian.
I sincerely believe all of the above, but I don’t know that it’s true.
One might assume that I’m going through a phase of existential angst and serious doubt about my faith, but I’d disagree. To me it’s just part of living out my Christian life.
Because I believe I can be a faithful Christian, and yet not claim to know the truth.