Secret or Public Prayers?

Many prayers in the Bible are alone with God.   Jesus teaches us to pray in secret. Matthew 6:6 But when you pray, go into your room and shut the door and pray to your Father who is in secret. And your Father who sees in secret will reward you. But understand the context; here the religious leaders liked to be seen praying, not so God would see hem, but so man would see them (and look spiritual). So public prayer especially in our churches is wonderful, see Matthew 18:20 For where two or three are gathered in my name, there am I among them.