Matthew 6:7
And when thou art at prayer, use not vain repetitions, like the heathen: for they imagine that they shall be heard for their much speaking.
Matthew 23:13
Wo unto you, scribes and Pharisees, hypocrites! because ye shut up the kingdom of heaven from men; for ye yourselves enter not in, and those who were coming in, ye suffer not to enter.
Luke 13:25-28
When the master of the family shall have arisen, and shut the door, and ye shall begin to stand without, and to knock at the door, saying, Master, master, open it for us! and he answering will tell you, I know you not whence ye are:
1 Timothy 2:8
I will then that men pray in every place, lifting up holy hands without wrath or doubting: