Matthew 6:1-7 KJV
1 Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven. 2 Therefore when thou doest thine alms, do not sound a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward. 3 But when thou doest alms, let not thy left hand know what thy right hand doeth: 4 That thine alms may be in secret: and thy Father which seeth in secret himself shall reward thee openly. 5 And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward. 6 But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly. 7 But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking.
When we do something good for others, we are to do so quietly because we are supposed to do it out of love and not for recognition. If we make a big deal about it, then the recognition of men is our reward and we will miss out on the blessing from God.
The same is true of our prayer life. We pray to communicate with God. Even if we do pray in a group setting, our goal is communication, not expectation that others will compliment our prayers. We need to make sure that we do what we do out of love and relationship and not because we are expecting some kind of earthly reward.