The condition of a man’s heart will determine whether his prayer will be answered or not. The truth is that a sinning person can not pray with a faith-filled expectation to receive from God. This is not because such cannot open his mouth to pray but because there is a quarrel between him and God.
It is natural for people to avoid the people they are not on good terms with, sinners feel the same way and avoid prayer because they have no living relationship with God.
To us children of God, prayer is more than a means of receiving from God but for fellowship and communion. As long as the relationship is intact, prayer will be beautiful and effective.
Our reading of the day highlighted this obvious truth. As long as there was no sin in the garden, Adam and Eve fellowshiped with God and they enjoyed it. But the moment sin came, they could not come out to face God.