According to John Piper in Desiring God, there are three stages of worship:
Starting from the final stage, he writes that "we feel an unencumbered joy in the manifold perfection of God" in which "we are satisfied with the excellency of God, and we overflow with the joy of His fellowship" (96). This is when you feel like bursting into praise songs and constantly want to praise His name because all your worship comes genuinely and instantaneously from the heart.
The second stage is where we "taste" but "do not feel fullness, but rather longing and desire." We know that God is good, and we still "recall the goodness of the Lord-- but it seems far off" (96). During this stage though, we should not be discouraged and instead have hope that God will bring us back to the final stage again.
The first stage is the lowest stage of worship. Piper writes that this is "where all genuine worship starts, and where it often returns for a dark season... [it] is the barrenness of soul that scarcely feels any longing, and yet is still granted the grace of repentant sorrow for having so little love" (96). Maybe we do not feel anything in our hearts, but as long as we continue to seek God because we are sinful beings, then He will fill us with fervent joy once again.
Reading these words was so encouraging to me because often I find myself becoming complacent or falling into a routine and forgetting why I praise God or do certain things. When we find that we don't have that same passion as we first did, it's okay. Instead of despairing and thinking God's not there, we need faith to trust that God will fill us up with fervor once again =)
How great is our God!