Your characters' condition will certainly not stay 'Good' forever. This is a list of all the conditions that can affect your characters. All but the fatal conditions have a plus/minus rating which indicate the level of the protection/severity of the ailment. Remember that if any of a character's stats is lowered to 0 or less by a status ailment, the character may very well die from the ailment.
Positive status changes:
These are the ones you WANT to affect your characters. All except "In Love" will expire when you rest, however.
Blessed: Increases your AC by 1 for every level of the bonus.
Holy Bonus: Increases the maximum damage you can inflict by 1 for every level of the bonus.
Power Shield: Reduces the amount of damage inflicted on you by 1 for every level of the bonus.
Heroism: Increases all your stats by 1 for every level of the bonus.
In Love: This is the only positive status change that doesn't expire when you rest. There's only one way to be affected by this "ailment", and that's by visiting the nymph Athea in the southwest corner of Area A4. When in love, all your stats are increased by 1 at first. With time, your love will increase and so will the bonus. However, when this bonus reaches 10, you will soon become affected by the Heart Broken ailment.
Minor Status Ailments:
All you have to do to get rid of these is have your party rest.
Asleep: The character has fallen asleep, either by magic or simply from extreme exhaustion. While asleep, the character cannot act, and will skip his combat round. If hit, the character will probably wake up. You can also cure this by casting the Awaken spell. (which will instantly awaken ALL party members, by the way)
Confused: The character won't be able to tell what the heck's going on and will be totally unpredictable in combat, sometimes even hitting the other party members.
Weak: Decreases all of the character's stats by 1 for every level of severity. The Revitalize spell will cure this as well as resting.
Drunk: You've drunken a little bit too much, have you? This is a very strange ailment: It increases your Personality and Luck by 1, while decreasing all the other stats by 1. Oh, and you're not getting rid of it easily... after you become sober again, you will be affected by the "Weak" status ailment: A hangover! :)
Major Status Ailments:
These will remain even if you rest. In fact, all of these except "Cursed" will even become more severe if you rest without curing the ailment first.
Cursed: There are two forms of curse. One affects the character: It lowers the character's Luck by 1 for every level of severity. The other is much worse: It affects the character's equipment. This curse will remove all abilities from the item until it is uncursed. For example, cursed armor won't give you an AC bonus, and cursed weapons will always deal minimal damage. The only way to remove a curse is at a Temple, with the Uncurse option.
Poison: Very annoying. It decreases your Might, Speed and Accuracy by 1 for every level of severity. You can reduce the level of severity with the Suppress Poison spell, or remove the ailment with the Cure Poison spell.
Disease: This too is a very annoying ailment. It decreases your Intelligence, Personality and Endurance by 1 for every level of severity. You can reduce the level of severity with the Suppress Disease spell, or remove the ailment with the Cure Disease spell.
Insane: If you've always wanted to be more like Kefka, this is the ailment for you! It will increase your Might and Speed by 1, but decrease your Intelligence, Personality and Accuracy by 1 for every level of severity. The only way to cure it is at a Temple or a certain Zingaro gypsy wagon.
Heart Broken: The proof that unanswered love can kill. If you remain affected by the In Love "ailment" too long, you will become Heart Broken, which has the same effect as Weakness: All your stats will decrease by 1 for every level of severity (which will increase over time). However, this ailment, as opposed to Weakness, cannot be cured in any way except by receiving healing at a Temple.
Fatal Status Ailments:
If all party members fall victim to one of these ailments, you will be wiped out. As in: "Game over, man."
Paralyzed: The character is completely immobilized and won't be able to act at all in combat. In addition to resting, you can also cure it with Cure Paralysis spell. Don't underestimate the severity of this ailment; in this game, you will be instantly wiped out if all your party members are paralyzed.
Unconscious: If your Hit Points fall to 0 or less, you'll fall unconscious. Some monsters also have the ability to knock you unconscious with a single blow. To recover, all you have to do is raise the affected character's HP above 0 again with a healing spell, or rest.
Dead: If an unconscious character is hit hard, any of the character's stats is lowered to 0 or less... there are many things that can potentially kill you. The safest way to be brought back to life is at a Temple. You can also use the Raise Dead spell, but it's risky. (see the spell list for details)
Stoned: No, this doesn't mean the character's been smoking too much pot, it means his flesh has been converted into a less convenient material. This lowers the character's HP to 0 in addition to bringing the character into a dead-like state. Cure it with a Stone to Flesh spell: The character will be unstoned and revived with 1 HP.
Eradicated: This is pretty much the worst thing that can happen to a you: You're not only dead, but all your flesh and vital organs have been disintegrated, leaving nothing but a skeleton. A Raise Dead spell doesn't work, since... well, there's just not enough left to raise. Take an Eradicated character to a Temple to get him/her resurrected. A Resurrect spell will work too, but it has great risks. (see the spell list for details)