Fruit of the Spirit is Joy

The fruit of the Spirit is joy. Joy starts with God, before the foundation of the world. Ultimately, joy is God's enjoyment of Himself in a Trinitarian fashion. The Father enjoys the Son, and vice versa. Therefore, if the Spirit is in us, we will enjoy God. We will enjoy His presence, His character, His children, His works (creation, redemption and providence) and His will. If you have joy in these things, then the Spirit dwells in you. If you don't enjoy them, then you are without the Spirit.