Matthew 6:7
"And, when praying, use not vain repetitions, as the gentiles do; for they think that for their much speaking they shall be heard.
Matthew 23:13
"But woe to you, scribes and Pharisees, hypocrites! because you shut up the Kingdom of Heaven against men; for ye do not enter, neither do ye suffer those who are entering in to enter.
Luke 13:25-28
When the Householder rises and shuts the door, and ye begin to stand without and to knock at the door, saying, 'Lord, open to us!' and He, answering, shall say to you, 'I know you not, whence ye are;'
1 Timothy 2:8
I desire, therefore, that the men pray in every place, lifting up holy hands, without wrath and disputing;