It's not so much that my newbie players want their characters to be evil. If they did I would have a much easier time mediating this - I would advise them to shift alignments and deities accordingly.
The problem is the players in question have created character they intended to be good characters. So much that they have goals that say 'when I grow up (level up) I want to be a part of a good organization that fights against evil!'
But, being newbies, they don't think things through before getting into the thick of the action. And when things go wrong, they freak out and do things that violate their chosen alignment.
Example:
The last game session featured the players sneaking onto a large sailing ship, to get back goods stolen from a merchant prince. It was made very clear to the PCs that these goods were stolen as part of a political subplot between various merchant princes, rather than piracy or direct thievery. Through their investigations they found that it was a personal vendetta between the Captain of the merchant vessel and the rival merchant prince - aka the vast majority of the crew is not in on this and is just a guy doing his job.
The rest of the party sneaks on board. The fighter/mage had been assisting them by creating a diversion, finds himself stuck onshore without the rest of his party. It is safe onshore, but when he sees bad stuff happening to his friends, he decides he needs to get on the boat, now. He can't swim. He has low dex and charisma, and doesn't think he'll make it past the sailors guarding the plank. So he asks 'if I dress as a sailor, can I just pick up some cargo and walk on' and the answer is 'yes, that is likely. There are a lot of sailors loading cargo.'
So he decides he's going to knock out a sailor and steal their clothing. But he doesn't think the plan through. He calls one sailor off, lying about some damaged cargo, and then he tries to cold-cock the guy. Except he doesn't have any particular skill at hand to hand so when he rolls, he ends up just starting a fistfight and punching the guy. And the sailor, getting a fist in the face, punches him back. They skirmish for a round or two, doing about 4 points of (we were counting as non-lethal) damage each. I narrate that the fight is becoming loud and starting to draw attention. My player panics, and uses shocking grasp on the sailor. Which kills the man, instantly.
[reference: PC has 21 HP / Sailor has 6HP / Shocking Grasp: 1d8+6]
To which one of my veteran players turns around, shocked and asks 'did you just kill that guy? That's evil...'
The newbie returns 'It was self defense!'
Veteran player replies 'you lied to a guy who was just doing his job, lure him into an alleyway, punch him - and then you get surprised when this crusty sailor type hits you back? And use a lethal spell on him?'
The newbie replies 'Well, the last bad guy we fought didn't go down so easily, I didn't realize sailors were so easy to kill...'
Which started the discussion of alignment and what to do with said player. And to find ways to describe to the play what it meant to be neutral good, and how to prepare your fights better if you're trying to not seriously injure someone.
It's a learning process. They are newbies. I'm just trying to find ways to communicate what they need to learn to them better