1Corinthians 4:1-5 (NIV): 1So then, men ought to regard us as servants of Christ and as those entrusted with the secret things of God. 2Now it is required that those who have been given a trust must prove faithful. 3I care very little if I am judged by you or by any human court; indeed, I do not even judge myself. 4My conscience is clear, but that does not make me innocent. It is the Lord who judges me. 5Therefore judge nothing before the appointed time; wait till the Lord comes. He will bring to light what is hidden in darkness and will expose the motives of men's hearts. At that time each will receive his praise from God.

In this passage, the apostle Paul warns us not to judge others but instead to leave the judgment business up to the Lord upon his return. Instead of making judgments about others we ought to be concerned about our own lives; stay faithful to what has been entrusted us by God. 

How does this passage apply to believers today?  Sadly, the church often does display judgmental attitudes. Furthermore, active church folk often expect recognition of their contributions or their gifts. This passage addresses both these attitudes.  "Judge not" and "trust that God will reward for faithful service" would be two prime themes to be developed into a sermon from this passage.