White cards
Aegis of Honor Since its good only against red, Sanctimony and surely CoP:Red are better and more consistant even red has creatures.
Ancestral Tribute The joke rare that can do a lot but never sees play. 7 mana to gain lots of life that wont help you, since youre in your 10th-11th turn and your opponent already got so many of your cards you gonna die anyway. If you used cards to get quick Threshold, just useem and win more easily.
Angelic Wall Great defender for all those 3/Xs. Still there are better bears for 1W (and super-bears for WW if you play with lots of white mana).
Animal Boneyard The only enchant land Id have to think whether to put in my deck or not. The red is terrible and the rest go in, this one gives you life for a dead creature, which is pretty good, but it isnt enough, when you have much other better cards.
Auramancer Why would you use such a useless card when Treasure Hunter did more for the same cost and is more effective by 1 millionth of a %.
Aven Archer Take Heavy Ballista. Give it 0/-1 and flying. Good so far. Add W to the cost making it double cost. Now its Solid. Add 2W to the activation cost of the damage. Now its bad.
Aven Cloudchaser I dont know why they keep printing cards so youd play 8 of them, while you barely play 1 in constructed. Solid 2/2 flier for limited and it doesnt hurt that it can destroy something else as well.
Aven Flock Nice flier to play with in limited. Costs too much for any other format.
Aven Shrine Gaining 6 life from 4 copies of 1 spell (not a permanent) along with this card is not a combo or even close. Its even far from being pathetic.
Balancing Act Consider it this way It costs like Wrath of God and has no real other use except land destruction. If you have 4 mana against land destruction you should win. In short play the Wrath, or even Rout.
Beloved Chaplain Not bad for creature wars, though easily removed. Nice first round pick for drafts.
Blessed Orator Nice hoser, good pick and best against burn and mirror matches of creatures.
Cantivore A lot worse than such white rare creature you wont find. Just play Replenish decks and be happy.
Cease-Fire Orims Chant made a much better job and it wasnt a good pick against mere creatures.
Confessor With all the discarding going around in limited it has a spot from the sideboard against Mind Bursts, Last Rites etc., though only in limited.
Dedicated Martyr Not bad if you lack 1cc creatures, but even then its merely a chump blocker. Still, any 2/X for 2 mana is better even if you have no other 1cc creatures.
Delaying Shield Along with bouncing it each time you take more damage than you can hold is good. The problem is that you waste lots of mana before you can cast anything during your turn. Definitely not the right way to stop Urzas Rage (see Aegis of Honor for comments as well).
Devoted Caretaker Finally an ability that justifies its rarity. When you need two cards to kill a threatning creature, which is merely 1/2, must be good.
Divine Sacrament Crusade for 1WW. Threshold makes it double effective. If you played WW with Crusade and switched to Glorious Anthem, switch back to this thing. Just add 4 Sac-land and youll get the double shortly.
Dogged Hunter Green likes fatties for low mana cost. White doesnt like green messing up his plans, so he made this dude. Squirrels, Elephants, Wurms are dead, even a Rhino for all I care. Should be able to catch greens pants down.
Earnest Fellowship Its not a Bedlam unless its mono vs mono and still I rather splash for red to have Chaos for that effect.
Embolden I love this card. 2W to prevent 4 damage however you wanna, but I like the 3WW to prevent 8 damage however you wanna (Flashback: 1W). Awesome in sealed and the more the merrier.
Gallantry Reprinted from Whetherlight and rightfully so. With all the fat green holds you want a white protector for a w/u deck.
Graceful Antelope I dont like this creature one bit and it has nothing to do with plainswalking. WW will be back now and 1 damage each turn wont make the difference with the Divine Sacrament or without it.
Hallowed Healer Damage prevention in Sanctum Custodians form and better. 0/-1 for Threshold of additional 2 points of prevention. 2 of these are as great as 2 Samite Pilgrims were and probably better. I wouldnt suggest playing it on the other formats though.
Karmic Justice This card should be found at least with 3 of its copies in each sideboard of a deck with white. Should go in any deck against any deck, and theres no reason not to play without it.
Kirtars Desire Great, great, great. Although Pacifism is good, it holds a fat creature from doing too much harm for mere W.
Kirtar's Wrath Bad Wrath with Threshold, worse without it. Limited only.
Lieutenant Kirtar A legend you can play more than one of and you should. Exile for 1W and sacrifice along with blocking a creature is quite good. Dont forget its a 2/2 flier for 3 mana anyway.
Life Burst If you got 4+ in a draft you can play them, otherwise forget it. Although 3 is a start (gives you 24 life total), 4 is a minimum (40 life total). While 5 copies of any card are allowed in drafts, youd surely get some at the latest picks.
Luminous Guardian Serves as a mighty wall and can hold lots of Squirrels. Still its rather expensive for use and cant keep most fatties for too long.
Master Apotherapy Although it costs WWW, its great if you have at least 2 more clerics (except Hallowed Healers) and if you play white as main color.
Mystic Crusader Its not Paladin en-Vec and it would never be one either. It lacks first strike to compete against non-black non-red, and X/2 fliers can be killed easily by most fliers.
Mystic Patient a great 1/1 that isnt worth to kill, though you wont attack against either. Becomes very solid as Diving Griffin when you have Threshold.
Mystic Visionary Not bad for early game, but has very little effect even with its flying. Shouldve gotten at least +0/+1 except for the wings.
Mystic Zealot Coalition Honor Guard was a great blocker and could make some damage as well. Except for the change of abilities the Zealot is a fair 4cc creature. Along with Threshold its deadly as hell, serving like a Wall of Swords that can attack (even for the same cost).
Nomad Decoy The only thing I have to say about this creature is that without red and/or black you better get 2 more creatures and fast. This guy with the Threshold is worse than most fatties, tapping 2 creatures for mere WW. In short get rid of it fast or pick it first before it gets kidnapped.
Patrol Hound It aint no Wild Mongrel, but it has potential holding most of those pesky X/2 creatures.
Pianna, Nomad Captain - Soltari Champion without shadow and attacks as 3/3. What more could you ask for?
Pilgrim of Justice This pro-red fella holds the big Xs out and those pesky fatties as well along with reds quick Mad Dog and Minotaur Explorer, which black doesnt have to offer.
Pilgrim of Virtue The pro-black guy has very little to offer, see the pro-red dude for more details.
Ray of Distortion Disenchant for 3W!! Over costed like hell, and is there just for its Flashback (which costs 4WW). For constructed it might have some effect against pesky enchantments/artifacts like Kirtars Desire, Chamber of Manipulation, Casutic Tar, Squirrel Nest, Steamclaw, etc. And thats why it has no reason to be played out of a limited decks sideboard.
Resilient Wanderer Not bad for limited, bad for the rest, like most cards in this set.
Sacred Rites For 1W Shiled Wall gave you +0/+2. To do the same here you need to play 3 cards (Rites + discard 2). No further questions.
Second Thoughts Overcosted, but 2WW would make it problematic as a splash, in which case it serves wonderfully. Save it for the real fatties.
Shelter One of my favorite non-creature cards in the set for limited. Usually helps killing a creature and can recycle itself easily.
Soulcatcher If fliers you control die this means this one probably died first, but theres nothing wrong with turn 2 flier anyway.
Sphere of Duty, Grace, Law, Reason and Truth Except for Duty, no sphere has place in maindecks of limited decks. No sphere has place even in the sideboards of decks that arent limited, except for Law.
Spiritualize At first I thought it was Reverse Damage for a creatures damage. It doesnt prevent the damage, therefor barely useful. Nice to have it against a Rabid Elephant blocked by 4 1/1s and gain 11 life and draw a card. Not nice having it in 99% of the other cases.
Tattoo Ward Except for the fact it ruins enchantments it doesnt do anything really, except destroying other enchantments on the creature. The +1/+1 is really invalid here.
Testament of Faith For W, this Enchantment-Wall is great to have. It has two good uses, blocking and Threshold helper (pay 0).
Tireless Tribe Riddle: What can kill all X/1s and stay alive unless you need more than 2 cards (in case X>4)? Answer: This creature. Great protector against all those pesky 3/Xs and 4/Xs. Each card simply becomes Fend Off.
Try to see what happens when you make it bigger.
Wayward Angel Serra for 4WW is an overcost. Believe me itll be destroyed way before it gets Threshold. If not, Serra wouldve been better anyway.