A lot of paladins are aware that Glyph of Divinity and Protector of the Innocent are rather solid choices but one that gets over looked every now and then is the Glyph of Beacon of Light. This is the glyph that removes the global cooldown (gcd) from the beacon of light spell. If you don’t know, a gcd is the small delay before you’re allowed to use another instant spell or begin casting/channeling again. Typically a holy pally’s gcd this tier is anywhere from 1.2 to 1.3 seconds (it matches your Flash of Light cast time).
What this means for the play style is typically two scenarios that are similar to one another. First is you finish casting a spell, change your beacon target and immediately cast another spell. The 2nd is you use an instant spell and then change your beacon target while you’re still in the middle of the gcd from your instant spell cast. Both of these would pretty much cause you to have no delay or time lost at all from changing your beacon target. an uncommon situation is also if the tanks are not taking boss hits but the raid needs healing then you can rapidly switch beacon to various dps who need healing while spamming the raid to lower beacon overheal.
“But why should I even care to micro manage this as after all 1.2x seconds is hardly anything?” This isn’t an uncommon thought but is wrong. Managing gcds is still an important task especially this expansion with how our instant cast spells are our top healing abilities. What removing the gcd realistically means is after you cast beacon of light, rather then standing still for 1.2x seconds you instead cast an extra heal. Think about how you could cast a holy shock for 45-50k+, or an eternal flames 80-90k healing (plus the hot) during the time that you would otherwise be waiting on the beacon gcd. Now consider a fight with 5-10 beacon swaps and all of a sudden being able to use that many more instants or partial cast-time spells adds up quite well in healing value gained (especially since those rough numbers didn’t include absorb and beacon transfer values).
Another important gain is tank swaps on hard hitting bosses. This expansion has already had several of those where cooldowns and fast reactions are a must. In this case being able to change beacon on the taunt swap and immediately use an instant or cast Divine Light on them with no delay from the beacon cast can be invaluable.