http://www.twinkinfo.com/f2p-twink-guides/24217-f2p-20-holy-paladin-guide.html last post on first page. A detailed explanation.
on first button in action bar 1 2 3 4
/cast [mod:alt,target=Omgwtfsap] Flash of Light; [help,nodead,target=focus] Flash of Light; [harm,nodead] Crusader Strike
/click MultiBarBottomLeftButton1
/changeactionbar 2
/script UIErrorsFrame:Clear()
/cast [mod:alt,target=Omgwtflawl] Flash of Light; [help,nodead,target=focus] Flash of Light [harm,nodead] Judgement
/click MultiBarBottomLeftButton1
/changeactionbar 3
/script UIErrorsFrame:Clear()
/cast [mod:alt,target=Omgwtflawl] Flash of Light; [help,nodead,target=focus] Flash of Light [harm,nodead] Templar's Verdict
/click MultiBarBottomLeftButton1
/changeactionbar 4
/script UIErrorsFrame:Clear()
on second button in action bar 1 2 3
/cast [mod:alt,target=Omgwtfsap] Word of Glory; [help,nodead,target=focus] Word of Glory; [nodead,harm] Holy Shock
/cast Avenger's Shield
/click MultiBarBottomLeftButton1
/changeactionbar 3
/script UIErrorsFrame:Clear()
/cast [mod:alt,target=Omgwtfsap] Holy Shock; [help,nodead,target=focus ] Holy Shock; [nodead,harm] Templar's Verdict
/cast Avenger's Shield
/click MultiBarBottomLeftButton1
/changeactionbar 2
/script UIErrorsFrame:Clear()
/cast [mod:alt,target=Omgwtflawl] Word of Glory; [help,nodead,target=focus] Word of Glory; [nodead,harm] Templar's Verdict
/click MultiBarBottomLeftButton1
/changeactionbar 1
/script UIErrorsFrame:Clear()
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bound to W
/target [target=mouseover,nodead,exists,harm]
/focus [target=mouseover,nodead,help]
/click ActionButton2
bound to Q
/target [target=mouseover,nodead,exists,harm]
/focus [target=mouseover,nodead,help]
/click ActionButton1
You press lets say W which presses action button 2 in default action bar. Each macro has a /changeactionbar # which in turn cycles the macros so you just spam them and your abilities will go off depending what you have mouse over. You don't need to continuously mouse over enemies just when u have to heal since my setup Focuses ally>heals>clears focus else my setup wont work. It also makes switching specs easy since the setup works with anything and I don't have to move abilities around.