Believers do not naturally know what to pray for as they ought, but the Spirit of God helps them. He intercedes for the saints and helps the saints to pray aright in accord with the will of God. prayer should be Spirit-led.
And we pray:
O Spirit of God, we feel our weaknesses. We feel also deep groanings within us to pray to You, but we often fail to know what to pray for or what to say. We can only rely on You to guide us and strengthen us through Your Word. Let us not ask amiss, in selfishness, but ask according to Your Will in Love and faith, Amen.