There are a lot of differences between Christian denominations—that's why there are denominations in the first place—but those differences run deeper than worship style or whether the minister wears a robe.
Denominations are differentiated by their core beliefs, the doctrine they follow, the theologians and leaders that influenced their early history, and how they view salvation and the sacraments.
Three main factors distinguish Christian denominations from one another. We won't be getting into specifics about individual denominations, but rather we'll be talking in generalities about the underlying principles that differentiate them.
Source of Doctrine
All religions have a source of doctrine, usually an ancient writing that they believe to be the inspired Word of God. For Christians, that means the Bible, including the Old and New Testaments. Many denominations, however, also look to other writings (from historical church fathers, theologians, creeds, and so on) as faithful interpretations and confessions of Scripture.
All Christian churches base their beliefs on the Bible, and most view Scripture as the inerrant Word of God. Some denominations—including the Catholic and Orthodox church bodies—also include some or all of the apocryphal books in their Scripture canon.
Most denominations have additional sources of doctrine in addition to Scripture. Lutherans have the Lutheran Confessions, Catholics have their own ancient writings, and most denominations have creeds and confessions they hold to.
Differences also occur in how those additional sources of doctrine are viewed. Some church bodies hold them nearly on the same level as Scripture, while others view them as simply an exposition or explanation of Scripture.
Role of Christ/Way of Salvation
Christianity is, naturally, centered on Christ. But differences can arise between bodies of the Church on the role that Christ plays in salvation, faith formation, and election.
Faith and Baptism
Christians believe that belief and faith in God provides salvation. However, church bodies differ on how faith is imparted to the believer.
Some denominations believe that faith is solely a gift from God—it is imparted to the believer in Baptism. In this case, the believer plays no role in his or her own salvation; both faith and salvation are completely found outside of the believer.
Others, however, assert that believers can play a role in their own salvation by making a conscious decision to accept Christ or come to Him on their own. In most of these cases, Baptism is merely an act of obedience, a symbolic representation of the conversion of a Christian; it plays no role in the actual salvation of a believer.
Some denominations hold fast that, while Christ died for our salvation, believers can contribute or appeal to God through good works or penance. Whether through prayer or confession, penance can be made for sins through the believer's own actions.
Role of Christ
Christians acknowledge that Christ died to save our sins. But some denominations of Christianity downplay Christ's role in salvation, or place it beneath the individual's role in salvation (e.g., what matters is that the individual chose to come to faith, not that Christ died to save him or her).
Sacraments play a key role in Christianity. Most denominations observe Baptism and Communion, whether or not they see either as necessary for salvation. But some denominations observe additional sacraments besides these two.
Baptism is observed in nearly every Christian denomination, but two major divisions occur in regards to the role it plays in salvation and whether it's a Means of Grace.
Certain denominations see Baptism as a Means of Grace, where believers receive faith and forgiveness of sins. Others see it merely as an act of obedience, a symbol of the new life the believer has chosen to accept in Christ.
Much like Baptism, Holy Communion is observed in almost all Christian denominations. Some view it as a Means of Grace, where believers receive forgiveness of sins. Other denominations see Communion as only a symbol or remembrance of Christ's death.
Other key differences occur in how church bodies interpret whether wine or grape juice should be used, and whether the bread and wine are just bread and wine, the actual body and blood of Christ, or both.
Certain denominations have additional sacraments, such as confirmation, penance, marriage, anointing, and holy orders.
So . . . what now?
Even though denominations have different beliefs about sacraments, doctrine, and the way of salvation, they are still bound together by Christ and the Word of God (provided they preach it faithfully). There will be Catholics, Baptists, Lutherans, Presbyterians, and Methodists in heaven, even if there are differences between them on earth.
No matter which denomination you belong to, you can always find common ground with other Christians. Discussing your theological, doctrinal, and sacramental differences can be beneficial for your own understanding of what you believe.
At the end of the day, always speak the truth in love to those whose beliefs differ from your own. Point yourself back to God's Word as the only true source of wisdom.
Interested in learning more about different denominations? Read a free preview of A Simple Explanation of Christian Denominations (and pick up a pack of 20 for your congregation).