We observe that every person has the goal of being happy or becoming happy. Even if their means may be mistaken, they still strive for the perfect good. This applies to every human being. Now we observe the following: Man tries to become happy or to be happy, and this is an unattainable act. It may be that things, feelings, dreams, and physical love may satisfy this; but this is only for a limited time—until a point when happiness disappears.
I answer: One cannot be happy either from oneself or from other creatures or created things. The goal is not to be happy, but to pursue beatitude—and this is Christ. Outside of Christ, there is no happiness. Everything that is good is perfect in him: perfect love, perfect happiness, perfect life.
Therefore, being happy in life is not the goal, but to behold beatitude. This takes place in eternity, where we will see God—face to face. This is the visio beatifica, the blessed vision of God.