A while back, a friend of mine mentioned to me that he had reexamined how he approached religions. He said he had for ages been trying to come to grips with them by reading their holy books, scriptures, and commentaries. But that has changed now. Now, he primarily seeks to understand a religion by observing how it inspires, motivates, influences, or determines the behavior of its adherents.
What would you consider to be the strengths and weaknesses of such an approach?
From personal experience with talking with seniors of said faiths and being on RF I noticed the best way to learn about a religion is practice it.
A few basics anyone can do without culture is meditation, ancestor reverence, acts of gratitude, prayer (however defined at that moment), acts of charity, and right speech and compassion.
These are general practices I souped up from other religions. All of them say books are not enough. A few said one needs community like African faiths, guidance (ideally) like Buddhist and Hindu, and discipline in all.
With books, I'd say brush up on its history, talk to more than one senior in faith and tell your friend he should come and talk sincerity of his search.
Some people get annoyed but that's better than insult. Go to a service at houses of worship. Ask what to wear and do.
Just be mindful you're not a practioner. I only know Protestant non liturgical Christians who are flexible in "membership."