"There are many who say, 'Who will show us any good?' LORD, lift up the light of Your countenance upon us. You have put gladness in my heart, more than in the season that their grain and wine increased."
Many pessimists are abroad today, especially in the religious world. Pessimism is a good cloak, (or so it is thought), for unbelief. David's hope was not in the things worldlings seek after (solely): money, clothing, houses, prestige, etc. David enjoyed, as all the godly do, a "secret feast" of the soul, whereby he was constantly nourished and refreshed.
See the kingdom with the eyes of faith in Jesus. Even today, partake of the realm of Christ's grace (in your soul). In this way, you carry about with you, even here, a real piece of heaven.
[Puritan quote of the day: "As God has two places He dwells in, heaven and a humble heart, so the devil has two places he dwells in, hell and a hard heart." --Thomas Watson, in "The Doctrine of Repentance"]