This lead me to wonder if I could really be in the right church if I didn't know what the other denominations taught. Would I need a degree in theology to determine the right denomination? Furthermore, where were denominations even in the Bible? No one talked about it much, and as an introvert I pondered these things in my heart without asking these questions. I would ask God about these things, with no answer (well, He began to slowly reveal an answer about 14 years later when an evangelical Catholic I worked with said, "Imagine what we could do against evil if we were united!)
The word "unity" never entered my ears as a young believer. Maybe I thought we were all united by the bond of our faith in Jesus. But this unity is not a true unity. One doesn't have to go through too many church splits (I've experience two church splits myself and one happened after I left a church and one happened to a church before we joined - that's 4 out of 5 Protestant churches we belonged to that I know had gone through a church split!) to figure out there ain't much unity going on within the body of Christ. This invisible "unity" was more of a common trait - the common trait of believing in Christ - than anything that bonded people together as one body.
So what does the Bible say about unity? In John 17:20-23 Jesus prays before his death that all believers would be one so that "the world may believe that you sent me". Jesus refers to his church as the kingdom of God and the kingdom of heaven many times through the Bible and in Matthew 12:25 Jesus warns that "Every kingdom divided against itself will be ruined, and every city or household divided against itself will not stand." Jesus' words express close unity.
Likewise, Paul insist on the unity of the church. In speaking to the Galatians he includes dissension and factions as sins of the flesh that will not inherit the kingdom of God (Gal. 5:20-21). In 1 Corinthians 1 Paul explains to the believers that they need to be unified. He asks the important question, "Is Christ divided?" In Ephesians 4 Paul emphasizes the importance of being one in unity and peace and warns the believers to not succumb to every wind of doctrine that will lead them astray.
Oh, so that's what the Bible says about unity. There is no Biblical evidence that denominations/divisions are the will of God. I want to be in the will of God. In order to be in God's will I have to give up my will. Even if that means going where I never thought I'd go.
This is a glimpse of what unity can be like. I say a glimpse because, while all Catholics share a visible unity, we have brothers and sisters in Christ who do not share this same unity. While this is awesome and exciting, it could be much, much more if ALL believers were united: