Still on acts that can inhibit your prayer the first act that can make your prayer a waste of time is "Don't pray like hypocrites do, don't pray to be seen". It is possible for your devotion to be a way of waste of time and another act that leads to that is UnforgivenessÂ
In Matthew 6:5 Jesus starts by telling us to not pray like hypocrites but as he says this he goes further to tell them how to pray in verses 9-13, so the context of the Lord's prayer in this bible passage is basically telling us things that can hinder your prayers.Â
Matthew 6:15 talks about how if we don't forgive others of their trespasses God won't forgive us
Another text of the Bible that further highlights that Unforgiveness can hinder prayers is Matthew 5: 23 where Jesus speaking says to drop all your gifts to God on the altar and make peace with your Brethren who have aught against you then return to him.
All this just goes to say that the grudge in your heart can render your prayer or worship(sacrifice) a waste of time.Â
Lastly another bible verse that uses the context of marriage to explain this is 1 Peter 3:7.