Desire is an inward longing for something we do not have but feel we need. Hunger and thirst are appetites God gave humans to make us aware of a need. Hunger for God's Word and His attributes are the spiritual appetite God gives Christians to make us aware of spiritual needs. Do pagans pray to their idols and ask them for love, joy, internal peace, kindness, gentleness, goodness, meekness, or self-control? They ask for other things—material things, material blessings.
God has given us faith to make us aware of spiritual needs. We are aware of our physical needs by nature, but we would never be aware of these spiritual needs unless God, by His Spirit, makes us aware. It is a loving gift from Him. He expects us to think about these needs and ask Him for them. Our very awareness of the need is a proof that God is working with us.
This adds another step to the process of answered prayer: There has to be an awareness of need followed by the desire to have what we need. The desire moves us to make it known to God, and if it is really earnest and fervent, it fixes our minds on the object of our longing, motivating our pursuit of it. In other words, desire sets the will into action.
What God really wants us to seek after, to desire, is Him, what He is.