Should I not go to church if I have not confessed my sins to others?

Answer:

"Therefore if you are presenting your offering at the altar, and there remember that your brother has something against you, leave your offering there before the altar and go; first be reconciled to your brother, and then come and present your offering" (Matthew 5:23-24).

First, notice that you read this backward. Jesus said that if you are aware that someone has something against you; so in other words, if you realize that someone is mad at you and not necessarily that you are mad at them. The section that these verses come from (Matthew 5:21-26) is about anger between two people. Jesus' point is that it is important to settle problems quickly, not putting off the discussion -- not even for worship.

Hatred is not a matter that can be ignored. A person cannot rightly worship God while holding a grudge against a brother (I John 3:15). Instead of harboring anger, problems between two people need to be straightened out as quickly as possible. Unresolved problems can quickly grow out of proportion and become major issues that are difficult to bring to an end. Notice the next verse: "Make friends quickly with your opponent at law while you are with him on the way, so that your opponent may not hand you over to the judge, and the judge to the officer, and you be thrown into prison" (Matthew 5:25).

"It is honorable for a man to stop striving, Since any fool can start a quarrel" (Proverbs 20:3).

"Be angry, and do not sin": do not let the sun go down on your wrath, nor give place to the devil" (Ephesians 4:26-27).

Therefore, this is not a verse about not going to worship. This is a verse about making peace with people as soon as you can.