I thought I had responded to this one, but, I am thinking that I started and stopped a few times. (Can't see it, so hoping I am not repeating myself)
I spent time in the Anglican church in my youth, and United Church of Canada in adulthood. My family was Christian. My references culturally and in the immediate family are all Christian.
There is significant material for me to study which discusses items in ways that I understand, that helps me explore faith from a Christian perspective.
I know that I only have so much time at my disposal, that study of faith is not my #1 priority.
How then to learn and practice faith with the responsibility that you speak about in the UU principles.
For me it meant sticking to the stories that I had learned and grew up with and looking at them through various lens. It is why this forum has been important to me.
I had a friend who left Christianity, and became a Buddhist monk. This person had degrees, religious training, etc, and decided Buddhism was her way. After a few years, she said a monk asked her, why she was there learning about Buddhism when her stories / life / roots were in Christianity. i am not expressing it well, but, basically that she could spend her lifetime learning buddhism, and not touch what she had learned already in her own faith...
She returned to Christianity and her own culture.
I get that for some it is important to be able to pull from multiple texts, or that for some, Christianity is just the wrong text, or that..for others, a defined faith with clear rules/meanings are where they start from.
For me, the United Church of Canada's unity of faith and exploration is important to me....and the max that I can handle in my exploration.