Personally, I have each of these on their own button, drive with my pally as the active toon and don't have keybinds for these.

However, I believe [combat] and [nocombat] are valid arguments.
For reference, check http://www.wowwiki.com/Useful_macros

Maybe something like:
#show Avenger's Shield
/cast [combat] Avenger's Shield
/castsequence [nocombat, target=player] Sacred Shield, Divine Plea, Avenger's Shield