Stanford Encyclopedia of Philosophy

This was a long article and I could not cut it shorter than this.
I found it very interesting. It seems like it tells me having virtues is somewhat inherent to the person!
Use the link to read the entire article if you will.

2. Virtue, practical wisdom and eudaimonia
A virtue such as honesty or generosity is not just a tendency to do what is honest or generous, nor is it to be helpfully specified as a "desirable" or "morally valuable" character trait. It is, indeed a character trait — that is, a disposition which is well entrenched in its possessor, something that, as we say "goes all the way down", unlike a habit such as being a tea-drinker — but the disposition in question, far from being a single track disposition to do honest actions, or even honest actions for certain reasons, is multi-track. It is concerned with many other actions as well, with emotions and emotional reactions, choices, values, desires, perceptions, attitudes, interests, expectations and sensibilities. To possess a virtue is to be a certain sort of person with a certain complex mindset. (Hence the extreme recklessness of attributing a virtue on the basis of a single action.)
The most significant aspect of this mindset is the wholehearted acceptance of a certain range of considerations as reasons for action. An honest person cannot be identified simply as one who, for example, practices honest dealing, and does not cheat. If such actions are done merely because the agent thinks that honesty is the best policy, or because they fear being caught out, rather than through recognising "To do otherwise would be dishonest" as the relevant reason, they are not the actions of an honest person. An honest person cannot be identified simply as one who, for example, always tells the truth, nor even as one who always tells the truth because it is the truth, for one can have the virtue of honesty without being tactless or indiscreet. The honest person recognises "That would be a lie" as a strong (though perhaps not overriding) reason for not making certain statements in certain circumstances, and gives due, but not overriding, weight to "That would be the truth" as a reason for making them.
An honest person's reasons and choices with respect to honest and dishonest actions reflect her views about honesty and truth — but of course such views manifest themselves with respect to other actions, and to emotional reactions as well. Valuing honesty as she does, she chooses, where possible to work with honest people, to have honest friends, to bring up her children to be honest. She disapproves of, dislikes, deplores dishonesty, is not amused by certain tales of chicanery, despises or pities those who succeed by dishonest means rather than thinking they have been clever, is unsurprised, or pleased (as appropriate) when honesty triumphs, is shocked or distressed when those near and dear to her do what is dishonest and so on.
Given that a virtue is such a multi-track disposition, it would obviously be reckless to attribute one to an agent on the basis of a single observed action or even a series of similar actions, especially if you don't know the agent's reasons for doing as she did. (Sreenivasan 2002) Moreover, to possess, fully, such a disposition is to possess full or perfect virtue, which is rare, and there are a number of ways of falling short of this ideal. (Athanassoulis 2000.) Possessing a virtue is a matter of degree, for most people who can be truly described as fairly virtuous, and certainly markedly better than those who can be truly described as dishonest, self-centred and greedy, still have their blind spots — little areas where they do not act for the reasons one would expect. So someone honest or kind in most situations, and notably so in demanding ones may nevertheless be trivially tainted by snobbery, inclined to be disingenuous about their forebears and less than kind to strangers with the wrong accent.
Further, it is not easy to get one's emotions in harmony with one's rational recognition of certain reasons for action. I may be honest enough to recognise that I must own up to a mistake because it would be dishonest not to do so without my acceptance being so wholehearted that I can own up easily, with no inner conflict. Following (and adapting) Aristotle, virtue ethicists draw a distinction between full or perfect virtue and "continence", or strength of will. The fully virtuous do what they should without a struggle against contrary desires; the continent have to control a desire or temptation to do otherwise.
Describing the continent as "falling short" of perfect virtue appears to go against the intuition that there is something particularly admirable about people who manage to act well when it is especially hard for them to do so, but the plausibility of this depends on exactly what "makes it hard." (Foot 1978, 11-14.) If it is the circumstances in which the agent acts — say that she is very poor when she sees someone drop a full purse, or that she is in deep grief when someone visits seeking help — then indeed it is particularly admirable of her to restore the purse or give the help when it is hard for her to do so. But if what makes it hard is an imperfection in her character - the temptation to keep what is not hers, or a callous indifference to the suffering of others — then it is not.