One of the most important aspects of prayer is an interior conversion of heart. Jesus himself stressed this idea to his disciples on multiple occassions.
The Catechism of the Catholic Church summarizes this teaching in its section on prayer:
From the Sermon on the Mount onwards, Jesus insists on conversion of heart: reconciliation with one's brother before presenting an offering on the altar, love of enemies, and prayer for persecutors, prayer to the Father in secret, not heaping up empty phrases, prayerful forgiveness from the depths of the heart, purity of heart, and seeking the Kingdom before all else. This filial conversion is entirely directed to the Father.
One of the clearest examples of this teaching is found in the Gospel of Matthew:
So if you are offering your gift at the altar, and there remember that your brother has something against you, leave your gift there before the altar and go; first be reconciled to your brother, and then come and offer your gift.
Jesus spoke repeatedly against those who would pray like hypocrites, focusing on the exterior signs of prayer, without looking interiorly.
The Catechism continues by saying how interior conversion opens us up to faith:
Once committed to conversion, the heart learns to pray in faith. Faith is a filial adherence to God beyond what we feel and understand. It is possible because the beloved Son gives us access to the Father. He can ask us to "seek" and to "knock," since he himself is the door and the way.
The next time you pray, pause a minute and think about the state of your own soul and what needs conversion.
