Question: "Why should I believe in organized religion?"
Answer: A dictionary definition of "religion" would be something similar to "belief in God or gods to be worshiped, usually expressed in conduct and ritual; any specific system of belief, worship, etc., often involving a code of ethics." In light of this definition, the Bible does speak of organized religion, but in many cases the purpose and impact of "organized religion" are not something that God is pleased with.
In Genesis chapter 11, perhaps the first instance of organized religion, the descendents of Noah organized themselves to build the tower of Babel instead of obeying God's command to fill the entire earth. They believed that their unity was more important than their relationship with God. God stepped in and confused their languages, thus breaking up this organized religion.
In Exodus chapter 6 and following, God "organized" a religion for the nation of Israel. The Ten Commandments, the laws regarding the tabernacle, and the sacrificial system were all instituted by God and were to be followed by the Israelites. Further study of the New Testament clarifies that the intent of this religion was to point to the need for a Savior-Messiah (Galatians 3; Romans 7). However, many have misunderstood this and have worshiped the rules and rituals rather than God.
Throughout Israel's history, many of the conflicts experienced by the Israelites involved conflict with organized religions. Examples include the worship of Baal (Judges 6; 1 Kings 18), Dagon (1 Samuel 5), and Molech (2 Kings 23:10). God defeated the followers of these religions, displaying His sovereignty and omnipotence.
In the Gospels, the Pharisees and Sadducees are depicted as the representatives of organized religion at the time of Christ. Jesus constantly confronted them about their false teachings and hypocritical lifestyles. In the Epistles, there were organized groups that mixed the gospel with certain lists of required works and rituals. They also sought to put pressure on believers to change and accept these "Christianity plus" religions. Galatians and Colossians give warnings about such religions. In the book of Revelation, organized religion will have an impact on the world as the Antichrist sets up a one-world religion.
In many cases, the end result of organized religion is a distraction from the intent of God. However, the Bible does speak of organized believers who are part of His plan. God calls these groups of organized believers "churches." The descriptions from the book of Acts and the Epistles indicate that the church is to be organized and interdependent. The organization leads to protection, productivity, and outreach (Acts 2:41-47). In the case of the church, it could better be called an "organized relationship."
Religion is man's attempt to have communion with God. The Christian faith is a relationship with God because of what He has done for us through the sacrifice of Jesus Christ. There is no plan to reach God (He has reached out to us"Romans 5:8). There is no pride (all is received by grace"Ephesians 2:8-9). There should be no conflict over leadership (Christ is the head"Colossians 1:18). There should be no prejudice (we are all one in Christ"Galatians 3:28). Being organized is not the problem. Focusing on the rules and rituals of a religion is the problem.