As an AoE damage spell, the DPS aefficiency of Consecrate is greatly increased for every enemy within the area. It is also a great way to deal damage to multiple enemies. Both of these factors make it an excellent spell for tanking.
Lightbringer Armor 4-piece bonus increases the damage dealt by Consecration by 10%.
Trivia
Consecration is a basic Paladin spell in Hearthstone. The flavor text reads: "Consecrated ground glows with Holy energy. But it smells a little, too."
Patches and hotfixes
Hotfix (2016-07-25): "Fixed a bug that was interrupting player loot windows when Consecration was active."
Patch 7.0.3 (2016-07-19): Now available to all specializations. Mana cost removed.
Patch 5.2.0 (2013-03-05): Base damage increased by 789%, and now scales less efficiently with attack power by approximately 11%.
Patch 5.0.4 (2012-08-28): Now a Protection specialization ability. Duration reduced from 10 to 9 seconds.
Patch 4.0.1 (2010-10-12): Consecrate now lasts 10 seconds but has a 30-second cooldown, and works with Holy Power instead of spell power. Major talent-tree revamps have eliminated many of the talents that formerly improved Consecration's performance. Many of the items that used to affect Consecration no longer have those attributes.
Fixed problem where occasionally repeated casts of Consecration will not deal damage.
The charges from the [Zandalarian Hero Charm] will now be consumed by melee and ranged abilities and spells which do non-physical damage. This includes: [Hammer of Wrath], Judgement of Righteousness, [Seal of Command], Judgement of Command, [Volley], and [Arcane Shot]. The trinket will also now burn charges from each casting of a damage over time spell, heal over time spell, and area aura spells such as [Blizzard] and Consecration. Only one charge will be burned per area spell cast, rather than multiple charges per target hit as was previously the case.
Patch 1.9.0 (2006-01-03): No longer displays a debuff icon on targets in the area of effect.
[Hallowed Ground]
[Hammer of the Righteous]: also causes a wave of light that hits all other targets within 8 yds for Holy damage.
[Light of the Protector]: increases healing by 20%.
[Shield of the Righteous]: effects increased by 20%.
Hotfix (2016-07-25): "Fixed a bug that was interrupting player loot windows when Consecration was active." 
Patch 5.2.0 (2013-03-05): Base damage increased by 789%, and now scales less efficiently with attack power by approximately 11%. 
Patch 4.0.1 (2010-10-12): Consecrate now lasts 10 seconds but has a 30-second cooldown, and works with Holy Power instead of spell power. Major talent-tree revamps have eliminated many of the talents that formerly improved Consecration's performance. Many of the items that used to affect Consecration no longer have those attributes. 
Patch 3.0.2 (2008-10-14): Now scales with attack power and spell power. 
Patch 2.2.0 (2007-09-25): Now properly hits large creatures. 
Patch 1.10.0 (2006-03-28):
[Zandalarian Hero Charm] will now be consumed by melee and ranged abilities and spells which do non-physical damage. This includes: 
[Hammer of Wrath], Judgement of Righteousness, 
[Seal of Command], Judgement of Command, 
[Volley], and 
[Arcane Shot]. The trinket will also now burn charges from each casting of a damage over time spell, heal over time spell, and area aura spells such as 
[Blizzard] and Consecration. Only one charge will be burned per area spell cast, rather than multiple charges per target hit as was previously the case. 
[Explosive Trap], 
[Hurricane], 
[Rain of Fire] and 
