"Therefore judge nothing before the time, until the Lord come, who both will bring to light the hidden things of darkness, and will make manifest the counsels of the hearts: and then shall every man have praise of God."(1 Corinthians 4:5)
Judging one another is something we often do. We see from the outside and pass the judgements in the courtrooms of our heart. We tend to view one another in that perspective. The Corinth church fell into this deception of judging the servants of God and taking sides. Remember it's taking sides between three giants of the scripture. Paul had the highest quality knowledge of the Torah and how the Lord Jesus became the fulfilment of the Law. He had deep spiritual revelations about the Lord Jesus. Apollos was very proficient in Greek and scriptures. His oratory skills and the way to put things in perspective was just praiseworthy. Who would not want to side St. Peter who experienced the Lord closely. Wherever he went, miracles took place. So the church was divided as they took sides and many a time the conflict became evident.
St. Paul appealed to the church to leave the judgement to God. The people were supposed to honor these men of God for what they preached. They were servants of Christ and were entrusted with the mysteries of God. The stewards ought to be faithful in their responsibilities. St Paul didn't glory over the appreciations and criticisms he received. He was of the opinion that human courts were too small to evaluate him. In fact Paul understood that even if he didn't find any wrong with himself, it was up to God to certify him. To stand before God and being accountable to Him is the greatest of all duties of man. The Lord would bring to light the hidden things of darkness and will reveal the thoughts and intentions of the heart. Hence our aim should be to get praise from God rather from mere men or oneself.
For further reading: Ecclesiastes 12:13-14, Matthew 7:1-5