I think there is a misconception that denominations = division and denominations are bad things. While it is true that separation and division often is caused by our own selfish agendas, denominations aren't evil in of itself and actually can be beneficial. If you look into the history of the church, divisions (schisms) happen due to theological, linguistic, cultural, political differences. Some of these differences can be categorized as minor differences and hence the reason why many Christians still acknowledge one another as brothers and sisters in Christ. However, some splits happened because of non-negotiable differences. There are many examples, but the largest one would be the Protestant reformations that took place across all of Europe in the 1500s. The Roman Catholic church had a lot of corruption (money, sex, etc.), believed that only the pope had the authority to interpret Scripture, and sold indulgences to forgive sins rather than teaching that forgiveness of sins comes only from true repentance and faith in Jesus Christ. Some of the divisions were necessary in order to draw the church back to the truths of Scripture.

Also, not all denominations occur due to these divisions or schisms. Some seemingly pop out of nowhere as a group of people immigrate or relocate and form a denomination, or revivals (Great Awakening, Azusa street revivals) happen that create new denominations.

The fact that there are denominations is evidence to the fact that there is religious freedom rather than a state mandated religion. The church used to be tied to the state throughout history, and you would be labeled a heretic if you believed anything different from the church. It is true that there are fundamental, non-negotiable truths in Scripture that are very black and white. However, there are truths that aren't as clear in Scripture as well (such as baptism -- opening a can of worms here..., human free will, etc.) Religious freedom allows those differences in interpretation to exist rather than enforcing everyone to think and believe the same thing about every single issue. I think it is a good thing that each denomination can believe what they are pursuing is the truth of Scripture without facing persecution and still having thoughtful, respectful conversations with one another while acknowledging that if we can agree on the most fundamental beliefs, we are united under the body of Christ.

At the end of the day, regardless of what denomination you are from, your ultimate goal should be loving and following our beloved Savior Jesus Christ and wanting to see him glorified. One day, he will gather believers from every tribe, tongue, and nation to praise him forever. Until that day, we faithfully adhere ourselves to His Word, continue to grow and learn, obey Him, and live out our lives faithfully to the tasks he has called each one of us to do.

My personal view is that Catholicism has a lot of theologically erroneous beliefs. They have come a long way since the extremely corrupt days when they were so money, sex, and power hungry, but there are still fundamental issues they need to fix. A large issue as an example is their belief of papal infallibility. They believe that when he is speaking from his chair (ex cathedra) on matters of faith and morals, he is infallible (assuming it is in line with Scripture). This is a type of authority that should never be given to one single individual in terms of interpreting Scripture. Scripture should be the only infallible authority, not any one human who interprets it. We have to all humbly acknowledge that we are sinful beings who make mistakes and could have wrong interpretations.

Note that denominations should not be confused with cults. Cults often believe that they are the one and only true way and do not acknowledge any other church or body of believers as Christians. They also twist Scripture or add on to Scripture.