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Fundamental Doctrine of Christianity: Believe in Jesus

Fundamental Doctrine of Christianity: Jesus: Amazing Love, Endless Grace, Eternal Life
That Fundamental Doctrine has never changed. It is simply to believe in Jesus, the Son of God. He invites all to "Come." Including you!

That Fundamental Doctrine has never changed. It is simply to believe in Jesus, the Son of God. “He invites all to "Come." Including you!

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Fundamental Doctrine of Christianity: Jesus: Amazing Love, Endless Grace, Eternal Life

Jesus* gave us the Fundamental Doctrine of Christianity in John 3:16:

For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.

(an asterisk after a name means there is a short bio of that person in my book SPIRITUAL LIVES.)

A short time later one of the thieves crucified with Him validated this text:

And he said unto Jesus, Lord, remember me when thou comest into thy kingdom.

And Jesus said unto him, Verily I say unto thee, To day shalt thou be with me in paradise. – Luke 23:42-43

50 days later Peter preached this message at Jerusalem and 3,000 believed and were baptized that same day!

The Apostles' first edition

Shortly after, Philip delivered the same message to the Ethiopian eunuch. The fundamental element was still there when Paul* and Silas ministered to the Philippian jailor, but they added a little to it:

And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house. Acts 16:31

As the disciples became missionaries to people who did not know Jesus, “believe” acquired a few more amplifications:

That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. – Romans 10:9

These things have I written unto you that believe in the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe in the name of the Son of God. 1 John 5:13

That Fundamental Doctrine has never changed

It is simply to believe in Jesus, the Son of God. It has never changed and remains the same today, praise God. “Whosoever” means anyone, and Jesus supplements this life-giving truth with an open and continuing invitation to anyone:

Come unto me, all ye that labor and are heavy laden, and I will give you rest. – Matthew 11:28

Through this fundamental doctrine and its loving invitation, the church grew. Thousands believed on the day of Pentecost, the day the church was born.

At first, all the Believers were Jews, and they wanted to bring their old religion with them.

When Gentiles believed, they resisted obeying Jewish laws that had no relation to them.

The Apostles themselves were divided on this issue, and they dealt with it through the epistles of the New Testament and by conferring with one another and seeking the guidance of the Holy Ghost.

This process set the course for developing teaching (doctrine) for the groups of Believers in what we now call the Church or Christianity.

Fundamental Doctrine Widens

The Didache and Apostles’ Creed laid the foundation for more fundamental doctrine, the Apostles’ Creed stating:

I believe in God, the Father almighty,

creator of heaven and earth.

I believe in Jesus Christ, his only Son, our Lord,

who was conceived by the Holy Spirit

and born of the virgin Mary*.

He suffered under Pontius Pilate,

was crucified, died, and was buried;

he descended to hell.

The third day he rose again from the dead.

He ascended to heaven

and is seated at the right hand of God the Father almighty.

From there he will come to judge the living and the dead.

I believe in the Holy Spirit,

the holy catholic* church,

the communion of saints,

the forgiveness of sins,

the resurrection of the body,

and the life everlasting. Amen.

*that is, the true Christian church of all times and all places

This was not a doctrine derived from consultation among the apostles or the consensus of the churches, but a statement of things the apostles believed. (“Creed” comes from the Latin word “credo” which means “I believe.)

At the time it was written people believed each of the twelve apostles contributed one of the twelve statements of belief.

Although it affirms belief in God the Father, God the Son, and God the Holy Spirit, it does not assert the divinity of the Son and Holy Spirit, which was a critical issue in the Arian controversy.

This creed was used as a structure for the first official statement of the doctrine of the Christian Church. Five more doctrines were added and deemed “Fundamental” in being necessary to belong to the Church of Christ in the Nicene Creed that solidified the fundamental doctrine of the church.

It holds to this day for both Roman Catholics and Protestants, although each has added elements pertaining to its own communion.

Fundamental Doctrine Documented

The Nicene Creed gives us the first definitive and official doctrines of Christianity, and they all hold to this day. The creed is based on the doctrine of the Trinity. Here is a summary of these official doctrines:

There is one God who exists in three persons.

God the Father is the creator of all things.

Jesus, as God the Son, suffered and died as a fully human being to save other humans from sin.

Jesus rose from the dead and is seated in Heaven as the Son of God.

God the Holy Spirit gives life to all things.

The Holy Spirit inspires people and shows them the will of God.

This creed has been foundational in defining Christianity to this day. It is accepted and recited in the Eastern Orthodox, Roman Catholic, and Protestant churches. They do not consider Christians those who do not accept the Nicene Creed, particularly the belief in the Trinity. Some of these are:

  • Quakers,

  • Jehovah’s Witnesses,

  • Oneness Pentecostals,

  • Christian Science practitioners and

  • Mormons.

There are those in the above churches that do believe in the original doctrine Jesus gave us in John 3:16, but they have interpreted “believe” in diverse ways, either excluding the understanding of Jesus as the Son of God or adding non-biblical doctrines.

All these groups came after the Protestant Reformation and out of Protestant churches that had added doctrines of their own, particularly the five solas.

Each of them too has idiosyncratic beliefs outside those stated in the Creed.

Protestants Update Fundamental Doctrine

As the Bible became more available and valued, reformers like Martin Luther*, John Calvin*, and Thomas Cranmer* challenged the doctrine of the Church in the 16th century.

Their “protests” against the Church’s authority resulted in the Protestant Reformation (1517), which saw the Bible as the final authority, not the Pope.

They developed Protestant Confessions, or statements of faith, like the Thirty-Nine Articles of the Church of England (1571) and the Westminster Confession (1646), that clearly stated doctrines for their church. Common among them were the five Sola’s:

  • Sola scriptura (“by Scripture alone”)

  • Sola fide (“by faith alone”)

  • Sola gratia (“by grace alone”)

  • Solus Christus or Solo Christo (“Christ alone” or “through Christ alone”)

  • Soli Deo gloria (“glory to God alone”)

Roman Catholic Fundamental doctrine

The Roman Catholic Church did not accept the sola’s and began a counter-Reformation (1563) to reassert and affirm Catholic doctrine.

Over the thousand years since the Nicene Council, the Church was the guardian of doctrine and the sole interpreter of it and its practice.

While the Scriptures remained central, tradition and the church itself were regarded as equal authorities and it could not accept the idea that Scripture, faith, grace, Christ, or God’s Glory could be alone, i.e., outside of the Roman Catholic Church.

Fundamental doctrines 16th century Fundamental articles (theology)

During the 16th century, some well-meaning Protestant and Catholic scholars tried to identify fundamental doctrines on which both sides could agree. At first, they proposed restating the Apostle’s creed and that all those believing it would be a part of the true church.

But neither side would accept this, and so the two groups continued to accept the Nicene Creed but each with its own unique add-ons.

Fundamental doctrine in the 19th & 20th centuries

As Darwinism and Biblical Higher Criticism challenged Christianity’s fundamental doctrine, many began to question the truth of their faith. Both Catholics and Protestants responded to this in separate ways.

The Roman Catholics proclaimed three new fundamental doctrines, the Immaculate Conception of Mary (1854) Papal Infallibility (1870), and the Assumption into heaven of Mary (1950).

The Protestants minimized the importance of doctrine and introduced modernism

Christian modernists emphasized feelings and the experience of God over strict obedience to biblical law.

Moreover, they welcomed doctrinal revisions based on developments in science and biblical understandings.

By the early 20th century, modernists became prevalent in many mainstream Protestant denominations, particularly Presbyterianism.

In response to this Believers faithful to the historic doctrine of the Nicene Creed defined anew the Fundamentals of Faith.

In 1910, the General Assembly of the Presbyterian Church identified what became known as the five fundamentals:

  • Biblical inspiration and the inerrancy of Scripture as a result of this

  • Virgin birth of Jesus

  • Belief that Christ’s death was the atonement for sin

  • Bodily Resurrection of Jesus

  • The historical reality of the miracles of Jesus

Other Christians picked up on these and added the Second Coming of Jesus. All of this has brought about a division in the mainline churches between the modernists and fundamentalists that continues today.

An ongoing trend we see today is for the traditionalists to withdraw from their liberal denominations to continue to worship traditionally honoring fundamental doctrine.

Fundamental Doctrine of Christianity today:

There are 2.8 billion Christians today. All of them know that fundamental doctrine Jesus gave in John 3:16. Do they all believe? I hope so; Jesus knows.

I believe the vast majority accept the Fundamental Doctrine of the Nicene Creed.

And that doctrine is important because it holds us all together, and we, the body of believers, are His body, and need one another.

We are also His Bride, the Church Universal, and He is coming back for us! Praise God.

One evidence of Jesus’ divinity is the truth of His Word and His faithfulness to it. It has held for 2000 years and will for eternity. How simple it is; Believe in the Son! Receive Eternal life! How can this be?

It is because of Who He is:

  • The image of the invisible God

  • He is before all things

  • He is the head of the body, the church:

  • He is the beginning, the firstborn from the dead.

  • He is preeminent.

  • He made peace through the blood of his cross,

  • He reconciled all things unto himself; whether they be things in earth, or things in heaven.

  • He gave his body to present you holy and unblameable and unreproveable in His sight

St. Paul – Colossians 1:15-22

Jesus Himself is the Fundamental Doctrine of Christianity. Listen to His testimony:

I am Alpha and Omega, the beginning and the end, the first and the last. Revelation 22:13

I know not why God’s wondrous grace

To me, He hath made known,

Nor why, unworthy, Christ in love

Redeemed me for His own.


But I know whom I have believèd,

And am persuaded that He is able

To keep that which I’ve committed

Unto Him against that day.

I know not how this saving faith

To me, He did impart,

Nor how believing in His Word

Wrought peace within my heart.

I know not how the Spirit moves,

Convincing us of sin,

Revealing Jesus through the Word,

Creating faith in Him.

I know not what of good or ill

May be reserved for me,

Of weary ways or golden days,

Before His face I see.

I know not when my Lord may come,

At night or noonday fair,

Nor if I walk the vale with Him,

Or meet Him in the air.

: Dan­i­el W. Whit­tle, in Gos­pel Hymns No. 4, 1883.

I know whom I have believed, and am persuaded that he is able to keep that which I have committed unto him against that day. Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus. 2 Timothy 1:12-13

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