Matthew 6:7
And when you pray, do not use empty repetitions as the Gentiles do. For they think that they will be heard for their many words.
Matthew 23:13
"But woe to you, scribes and Pharisees, hypocrites! For you shut up the kingdom of heaven against men; for you neither enter yourselves, nor do you allow those who would enter to go in.
Luke 13:25-28
When once the owner of the house has risen up and shut the door, you will begin to stand outside and to knock at the door, saying, 'Lord, open for us.' He will answer you, 'I do not know where you come from.'
1 Timothy 2:8
Therefore I want the men in every place to pray, lifting up holy hands, without anger or quarreling.