What is Christianity?

As a member of the Iglesia Ni Cristo, I identified as a Christian, but my theology was questionable (to say the least). I was not aware of the core beliefs of Christianity and had no idea about church history.  Many different denominations and religions also identify as Christians, but are teaching opposing beliefs. Mormons claim to be Christians, Jehova's witnesses claim to be Christians, and members of the INC claim to be Christians. All three claim to be Christians, but all have totally different beliefs. 

The followers of Jesus Christ were first referred to as “Christians” by the Gentiles of Syrian Antioch (Acts 11:26). The Greek word Χριστιανός (Christianos), meaning "follower of Christ", comes from Χριστός (Christos), meaning "anointed one". As someone who identifies as Christian, one must hold to certain essential beliefs. Similar to a person who claims to be vegan, there are certain parameters to what it means to be vegan. A vegan is someone who follows a lifestyle that avoids consuming animal products. Some vegans even avoid using products made from animals, such as leather, wool, and certain cosmetics or household items that are tested on animals. There is a specific definition of what a vegan is. Yes, there is a spectrum of what vegans may or may not practice, but there are essential guidelines that would qualify someone as a vegan. A person who identifies as a vegan is unlikely eats a steak regularly every weekend. That would be a contradiction to the set boundaries that define a vegan. This is the same principle that applies not just in Christianity, but all religions. There are specific beliefs someone must hold to be a Muslim or Hindu. This also applies to non-religious beliefs. There are also specific beliefs one must hold to be an Atheist. In Christianity, there are specific beliefs that one must hold to qualify as someone who has been born again (John 3:1-21). 

Core beliefs in Christianity include:

• Christianity is a monotheistic religion. It's the simple belief that there is only one true God. No other created being is not ought to be worshipped.
• Christians believe that Jesus is the Son of God, both fully divine and fully human. Jesus is part of the Holy Trinity along with God the Father and the Holy Spirit. As the Son of God, He eternally existed. He was the word at the beginning, through whom all things were made and later became flesh (John chapter 1). All things were created through Him and for Him (Colossians 1:16) Jesus is God who became flesh, who stepped into His creation and became the solution for sin himself. Nobody else could qualify. The Atonement is the sacrifice Jesus Christ made to help us overcome sin, adversity, and death. Jesus’ atoning sacrifice took place in the Garden of Gethsemane and on the cross at Calvary. He paid the price for our sins, died, and was resurrected. The Atonement is the supreme expression of the love of God the Father and Jesus Christ. Jesus is historically known as a man who lived in Israel two thousand years ago. He impacted human history like no other historical personality. Even our modern calendar splits time at the approximate date of the birth of Jesus, who Christians believe is the promised Messiah or Saviour. People often see Jesus as a good moral teacher or as a prophet, but the Bible tells us Jesus is “the image of the invisible God.” (Colossians 1:15). 
• The Trinity is the concept of one God in three persons: the Father, the Son (Jesus Christ), and the Holy Spirit. This is not a contradiction. The Trinity is one God in substance or one being and three persons who share the same divine nature. Or put it simply, there's one WHAT and three WHOS. Just like we share one "what", our substance or being (human being), God the Father, the Son, and the Holy Spirit all share the same being - God. However, each member of the Trinity is distinct in person and has different roles. The word trinity may not be found in the Bible, but the Bible clearly teaches this concept. 
• Justification is by faith alone, grace alone, and through Christ alone. Contrary to other religions, Christianity teaches that salvation is through Christ alone, and not Jesus+. Religion typically teaches one part Jesus, and one part works. Biblical Christianity teaches that through faith in Jesus Christ, one can be reconciled with God and receive salvation. Grace is God's unmerited favor to the ill-deserving. We violated God's moral law and we stand condemned. Romans 6:32 says the wages of sin is death. No amount of good deeds or rituals can earn us God's favor. Salvation is a gift from God, not earned through work or sacrifice (Ephesians 2:8-9, Acts 4:12, Romans 4:1-5). When we believe in God, the fruits of our beliefs are manifested in repentance and good works and not the other way around. Jesus' blood paid for all of our sins; past, present, and future. So how much is there left for us to pay? 
• Christians believe in the resurrection of Jesus Christ, affirming life after death and the hope of eternal life for believers. This is the defining belief that revolves around the Christian faith. If Jesus did not die and rise again, then everything about Christianity is in vain (Corinthians 15:14). Christianity is not just based on a myth. It's based on a historical figure: Jesus. His life, death, and resurrection are backed up by history and evidence. Even if the Bible did not exist, Christianity would still be true if Jesus died and rose back to life. No other belief system has the kinds of historical validation that Christianity has, This is what separates Christianity from every other belief system in the world. 
  
• The key component of Christianity is faith. A lot of people intellectually understand the core beliefs of Christianity and the core message of Jesus. However, they lack the faith to believe in it. In other words, they lack the trust to believe in God. Believing that God exists, or that Christianity is true is different from believing in God and Jesus Christ. Scripture says that it is through faith and by God's grace that we are saved. Faith simply means trusting. Salvation is not about the amount of faith or trust we have or can produce, but the object we place our faith or trust in - Jesus Christ. 
  

Religion typically refers to a system of beliefs, practices, rituals, and values centered around a higher power, deity, or spiritual principles. It is often described as a list of dos and don'ts that tells people how they can achieve salvation or gain access to God. Religion is all about doing something to get the desired result. Christianity is more than religion. Biblical Christianity is not about what we can do. It is all about all about Jesus Christ, his life, teachings, death on the cross, and resurrection. It is having a personal relationship with God, our creator. It informs our lifestyle and relationships. The story of the whole Bible from Genesis to Revelation is about God's love and redemption to His creation. 

What about all the different Christian Denominations? 

Similar to our previous analogy, there could be a wide spectrum of what it means to be vegetarian. There are Lacto-Ovo-Vegetarians (people who don't eat meat, fish, or poultry but include dairy products and eggs in their diet), Lacto-Vegetarians (similar to lacto-ovo-vegetarians, who exclude meat, fish, and eggs but consume dairy products), or Ovo-Vegetarians (they avoid meat, fish, and dairy but include eggs in their diet), etc. Despite the wide range of differences, a vegetarian is typically understood as a person who does not eat meat or poultry, but may still consume other animal products. The same concept applies to all the different Christian denominations.

Up until the early sixteenth century the Roman Catholic Church dominated the spiritual life of Europe. Afterward, Martin Luther and his supporters in the Protestant Reformation separated from Catholicism. The Bible then was translated into the language of the people. This led to a surge of diverse thoughts and differing perspectives on how various biblical passages should be interpreted. As a result of these disagreements, various Christian communities emerged, each comprising individuals who shared similar beliefs on what they deemed as essential aspects of the faith. But as we mentioned previously, there is an essential core of Bible-based beliefs shared by all Christian denominations. Those core beliefs are the salvific doctrines of Christianity. Different denominations may disagree on secondary doctrines (e.g. baptism) but still hold to the core tenets of the Christian belief. However. this does not mean that those doctrines are not or less important. Rather it points to the importance of the need to personally know scripture to be able to make informed decisions on what to believe about certain doctrines. There isn't a "true" or correct denomination. What you believe about certain doctrines is for you to decide based on your understanding of scripture. But truth should always inform our beliefs. Doctrine or theology may be perplexing at times. It may create division because it divides darkness from light, but that is what truth is meant to do. It takes work, energy, and time in the Word. Sound doctrine is harvested from a careful study of Scripture. It is not just the responsibility of Christian leaders, but should also be the pursuit of every believer.