Skills...

[Illusionist]

I'm lvl 21 with:

Heal - 5
Frostbite - 1
Lightning - 1
Resurrect - 1
Firestorm - 5
Ice Storm - 0
Drain Life - 3
Weakness - 0
Nightmare - 0
Magic Shield - 0
Blessing of Vitality - 1

I currently have 4 skill points to spend but don't know where they are best used. Please advise.

[FluffNStuff]

Lightning!

[Royce]

Lightning (should max before firestorm even).

Edit: Wait but put 1 in mana shield first. That's one of your most important skills, and only really needs 1.

[Illusionist]

Lightning (should max before firestorm even). Edit: Wait but put 1 in mana shield first. That's one of your most important skills, and only really needs 1. Did you as you said. Thanks.

[Snakespeare]

OK, I would do Nightmare and Drain Life, but too late... Maxed out Drain Life is pretty cool! And Nightmare can be used in a combo.

You can also create your own combo with Ice Storm/Firestorm

[Royce]

Drain life is primarily useful in PvP, and kind of weak in PvE. Nightmare I would recommend after Lightning which is the best attack skill considering AoE, damage, cost, and cooldown plus is has an armor reducing proc. There is also a combo for frost and fire like there is for ice and fire.

[Snakespeare]

You could have 5 skills to level 4 instead of 4 skills to level 5.

[LIGHTNINGLORD67]

First of all remove the skill point in frostbite lol. That's kind of a worthless skill.

Second, get one nightmare one weakness one mana shield and the rest in blessings.

EDIT: oh and one ice storm

[Royce]

First of all remove the skill point in frostbite lol. That's kind of a worthless skill.

Second, get one nightmare one weakness one mana shield and the rest in blessings.

EDIT: oh and one ice storm

Problems with your post:
1. The player was asking about distributing 4 saved skill points, not a respec, so you can't remove anything.
2. Putting 1 point in each debuff is a terrible strategy, and would be extremely inefficient mana use. Particularly at low levels where regen is scarce, it is better to max a small number of skills, and not spread your points.
3. The player only has one of the blessings, though I would probably recommend maxing BoV or Nightmare after lightning.
;)