Lesson 1: Essential Christianity

In this course we examine the characteristic beliefs of many religious groups. It is important to first explain essential Christianity before discussing erroneous beliefs. What is true Christianity? What fundamental doctrines are essential to Christian theology and help us to determine the credibility of a religious group?

There is one Christianity and one true church because there is only one God and one true gospel. The church is built on one foundation: the truth revealed in (1) the ministry of the apostles and (2) the life, ministry, message, and atonement of Jesus Christ. There is one foundation and one worldwide church.

The unity of the universal church does not mean that one organization is the whole church. No single organization fulfills God’s purpose for the church everywhere in the world. Jesus told his apostles not to expect all Christians to be in the same organization (Mark 9:38-39). An organization that claims to be the entire church of God on earth should not be trusted.

The unity of the universal church means that all local churches must hold to the doctrines of Christianity that were essential at the beginning of the New Testament church. During the first few centuries, the church wrote the Apostles’ Creed, the Nicene Creed, and the Chalcedonian Creed to state the doctrines that have been essential to Christianity from the beginning. A creed is a statement of foundational Christian beliefs.

Doctrines about the Trinity, the deity of Christ and the Holy Spirit, the atonement of Christ, and salvation by grace through faith are foundational to original Christianity.

This course is not designed to defend a particular denomination. Doctrines defended in this course include Trinitarian doctrines as expressed in the historical Nicene, Chalcedonian, and Athanasian creeds of early Christianity; the absolute authority of the Bible; and the evangelical doctrines of grace, faith, and salvation.

The following points are essentials of the gospel. It is possible for a person to be saved without fully understanding them. However, denial of any of these points takes away the foundation of the gospel. A person or organization that denies any of these essentials will tend to develop another gospel, trusting a false means of salvation.

When you share the gospel with someone, certain points will be especially important because of errors that he believes already. For example, if he believes that salvation is only through a certain organization, he will believe that the organization’s membership requirements are necessary for salvation. He needs to know that a person individually receives forgiveness and comes into direct relationship with God.

(1) God created man in his own image so that he could have relationship with him (Genesis 1:27, Acts 17:24-28).

This truth shows the purpose of our existence and the goal of salvation. This truth is contradicted by religions that do not believe in a God with personality who loves all people. This truth shows the real problem with the world; people are not in relationship with God.

► What if a person did not believe that God loves him?

(2) The first people sinned and became separated from God (Genesis 3:3-6, 8, Isaiah 59:2).

This shows the origin of sin and the reason for the world’s condition. The world has suffering and sorrow because of sin. There is still joy and purpose because of God’s design, but the world is not like God planned it to be.

► What if a person did not believe that sin is the real problem with the world?

(3) Each of us has committed sin against God (Romans 3:10, 23).

Each person is guilty of willful sin against God. There is not a person who has always done what is right.

► What if a person thinks he can justify the things he has done?

(4) Every person who does not find mercy will be judged by God and be condemned to eternal punishment (Hebrews 9:27, Romans 14:12, Revelation 20:12).

This shows the seriousness and urgency of every individual’s need for salvation.

► What if a person does not believe that there is a righteous God who will judge his sins?

(5) A person cannot do anything to pay for the sins he has committed against God (Romans 3:20, Ephesians 2:4-9).

Good works and gifts cannot pay for sin because sin is against an infinite God and because everything already belongs to him.

► What if a person believes that he must make himself worthy of forgiveness?

(6) There must be a basis for forgiveness because sin is serious and God is just (Romans 3:25-26).

God wants to forgive, but if he forgave without a basis, sin would seem trivial, and God would seem unjust.

► Why was the death of Christ necessary?

(7) Jesus, the Son of God, lived a perfect life and died as a sacrifice so we may be forgiven, be made righteous before a holy God, and have eternal life (John 3:16, Romans 5:8-9, 1 Peter 2:22, 24).

Because Jesus is the Son of God, his sacrifice has infinite value and provides a basis for forgiveness of anyone in the world. If he were just a man, his sacrifice would have limited value. If he were not God, he would not be able to completely save us, and we must find another way of salvation.

► Why do some religions teach that people must be saved by works?

(8) Jesus rose physically from the dead, proving his identity as the Son of God and demonstrating his power to give eternal life (John 11:25-26, John 20:24-28, Romans 1:4, Revelation 1:18).

Cults that deny the resurrection of Jesus usually also deny his deity and the sufficiency of his sacrifice for salvation. Then they invent another means of salvation.

► What are the things that we know because Jesus rose from the dead?

(9) The sacrifice of Jesus is sufficient for salvation (Ephesians 2:8-10, 1 John 2:2).

Salvation is by grace, through faith, in Jesus Christ alone, and not by good works. Many religions teach that a person can partially earn his salvation. This puts people under the control of a religious organization that tells them what to do to be saved.

► Why do some people think that they cannot be saved without their religious organization?

(10) God saves every person who admits he is a sinner, repents of his sin, and believes the gospel (Mark 1:15, 1 John 1:9).

No human organization has the right to add to the requirements for salvation or to offer a different means of salvation.

► What kind of person has the right to believe that he is saved?

(11) Repentance means that a person is sorry for his sins and willing to quit his sins (Isaiah 55:7, Ezekiel 18:30, Ezekiel 33:9-16, Matthew 3:8).

Repentance does not mean that a person must make his life perfect before God will accept him. Only God can deliver the unbeliever from the power of his sins. Repentance does mean that a person is sorry enough for his sins that he is ready to turn from them. If a person is not willing to turn away from his sins, he cannot be saved.

► Why can’t a person be forgiven without repentance?

(12) A repentant, believing sinner receives salvation when he asks God to save him (Romans 10:13, Acts 2:21).

Every person has access to God’s mercy because of Jesus. No institution or human agent is necessary for a person to receive God’s forgiveness. A person receives it individually and begins a direct relationship with God.

► How do we know that a person can become a Christian in a moment of time?