The existence of the ideal is evidence of its possibility.
Ever been inspired by a movie because of the values it portrayed? The story was challenging and beautiful, moving and uplifting. Then you come back to "reality" and realize that the players are just actors, the movie is based on a novel, and you realize that it is just a story. This "balance" between idealism and reality is aided by our own exposure to shattered dreams, burst bubbles, and unmet expectations.
We face this type of exposure to reality all the time. In fact, it begins to seem that everything and everyone has a seemy underside; a corrupt core predisposed to dishonesty and fraud. We learn to protect ourselves from getting hurt again. We adjust our expectations of people when we hear that a pastor has committed adultery, or a friend has been busted in an internet scam, or we observe everyday, garden variety hypocracy when people we know don't operate with integrity. By the time we "grow up" we have been conditioned to temper idealism with "reality." But, I am not ready to be done with idealism.
I have a book (though I never read it) titled The Way We Never Were. The premise of the book is that nostalgic reminiscenses of, say, the 1950s are unrealistic. There were no Leave it to Beaver households. It was all Hollywood hype.
I wasn't alive in the 50s so I don't know, but I want to argue the following point: If I can imagine a story with values in which all the characters operate with integrity and depth and idealism, isn't the fact that I can imagine such a thing proof, to some degree, that it is possible?
Now, if you choose to, you could let your mind run away with all of the examples of things that you could imagine that would be unlikely to happen (I will leave the examples to you). But don't do that. Instead, recognize that, nestled in this rant, is a call to live idealistically. Some people say it can't be done but I say the fact that you can be moved by the dramitization of such values is the evidence that you can be inspired to imitate such idealism.
Now, cut to Scripture as our example of idealistic living. The Bible is full of high ideals that God clearly expects us to pursue. I have met people who feel that even the call to live according to Scripture is unreasonable! To think this way is to completely miss the power of God's grace. It is possible to do right. It is possible to think clean thoughts. It is possible to envision people who interact with integrity and honor. It is possible to be a person who interacts with others with integrity and honor.
Such living demands that we focus not on the evil inclinations that bombard us but on the example of Jesus "who for the joy set before him endured the cross, scorning its shame, and sat down at the right hand of the throne of God (Hebrews 12:2b)." That is, instead of focusing on the seemy underside of things and giving place to our own propensity to imagine evil, we instead pursue the right path. But how? This is the point of grace. We have been given the power to live differently; on a higher plane!
Paul said, "Who will rescue me from this body of death? Thanks be to God—through Jesus Christ our Lord (Romans 7:24b-25a)!" We have been rescued from a worldy reality and called to higher things!