I mentioned this verse in my post on Christ's Kingdom and I would like to expand upon it a little. One way to define the Kingdom of God is God reigning in our hearts by the application of Christ's saving work by the Holy Spirit. Thus the fruits of the Holy Spirit (in this verse boiled down to righteousness, peace, and joy) are the manifestations of the Kingdom. This is a package deal. With the Kingdom you get righteousness, peace, and joy, not one of the above. With only one (or two) the others are defective.
Some might focus on righteousness to the exclusion of peace and joy. They might be very learned on how to apply God's law to all of life and very enthusiastic about submitting the world around them to God's standard, but they then cause church and family splits by a lack of forgiveness and patience and never rejoice over the blessings that we can enjoy but always focusing on what is wrong and what we are going to do about it. Of course this is not really righteousness.
Others might focus on peace to the exclusion of righteousness and joy. They say things like "doctrine divides" and call for everyone to set aside their differences and "coexist." They end up with a society that tolerates all kinds of wickedness and is without real unity to rejoice over. At best, they merely coexist (though sin will not even allow that); at worst, they all die from unrestrained sin. Of course this is not really peace.
And others might focus on joy to the exclusion of righteousness and peace. They are the happy-go-lucky libertines that can't stand peacefulness or righteousness. "Dude, who cares about being righteous, we're under grace. It's party time!" Well, God cares about righteousness, and this reminds me of the people who "sat down to eat and drink and rose up to play” and 23,000 of whom were killed in one day (1 Cor. 10:7-8). And thus the peace that they might dread is the peace of standing before a God that condemns them, so they must distract themselves with more entertainment. Of course this is not really joy.
It is very interesting to see what Galatians 5:19-21 says are the "works of the flesh" (opposed to the fruits of the Spirit): sexual immorality, impurity, sensuality, idolatry, sorcery, (i.e. against righteousness) enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, (i.e. against peace) drunkenness, orgies, (i.e. against joy) and things like these. And Paul warns the Galatians, as he warned them before, "that those who do such things will not inherit the kingdom of God." Of course, unpeacefulness and joylessness is unrighteous, and triple vice versa.
And so the answer is to manifest all three traits. If we see that we lack one of these things, then we should stop and reconsider what we are doing as what we are building might not be the Kingdom. Note that it is not to have none of them, but it is to have all of them, exceedingly. Apathy and lukewarmness is not an option. We must strive to walk in a manner worthy of the calling to which we have been called (Eph. 4:1). Let us have the righteousness that exceeds that of the Pharisees (Matt. 5:20), the peace that surpasses all understanding (Phil 4:7), and the joy that causes us to sing on our beds (Ps. 149:5). Of course this is only possible with Holy Spirit, and so let us pay very close attention to the Word of God, the sacraments, prayer, etc... and thus let us live for Christ's Kingdom.
"The night is far gone; the day is at hand. So then let us cast off the works of darkness and put on the armor of light. Let us walk properly as in the daytime, not in orgies and drunkenness, not in sexual immorality and sensuality, not in quarreling and jealousy. But put on the Lord Jesus Christ, and make no provision for the flesh, to gratify its desires." ~Romans 13:12-14