I've been away from wow for about a month or so, coming back to Mythic raiding on my holy priest. When I stopped playing it was ALWAYS be in Sanctuary. The idea was PoM on CD > CoH on CD > Serendipity stacks > Renew.
I was reading a few other posts and it sounds like now the 'new thing' is to be in Serenity and to glyph binding heal. Why? How does that effect priority? Obviously heals are situational and change, and not as simple as use this spell now, but I don't know how/when/why binding heal > renew? I wasn't able to find any recent guides or explanations here or on official page, and I know most sites are still 6.0 information.