How to Determine If One Is a Christian

Paul Before Agrippa

When Paul was on trial before King Agrippa, he used the opportunity to preach the gospel (Acts 26:19-23). One of the apostle’s goals was to persuade the king to become a Christian. Agrippa recognized this because he stated, “In a short time you will persuade me to become a Christian” (Acts 26:28).

We are trying to do the same thing today that Paul was doing on that occasion – trying to persuade people to become a Christian. However, if we are going to persuade them to become a Christian, we need to know what a Christian is. Also, they need to understand what a Christian is before they can be persuaded to become one.

So how can we determine if one is a Christian? How can one determine if he/she is a Christian or not? We can consult the Scriptures to find an answer.

Not Determined (Only) By…

First of all, we need to be aware that there are certain characteristics that could be cited in an attempt to prove that someone is a Christian. However, while these traits are necessary for Christians to possess, they can also exist in one who is not a Christian. Therefore, we should understand that there is more to determining if one is a Christian than the following:

  • Sincerity – Paul lived “with a perfectly good conscience” (Acts 23:1), even while he was persecuting Christians (Acts 22:4-5). In other words, he sincerely believed that what he was doing was right. Not only was he not a Christian at that point, he was also actively persecuting Christians.
  • Belief in Christ – In discussing the connection between faith and works, James cited the example of the demons: “The demons also believe, and shudder” (James 2:19). The demons believed, but they did not have faith. We know this because genuine Biblical faith is shown by our works (James 2:18, 24). Therefore, while the demons believed in God, they were certainly not Christians.
  • Being religious – While in Athens, Paul recognized that the people were “very religious,” yet the one true God was “an unknown God” to them (Acts 17:22-23). Jesus condemned the Pharisees and scribes for being disobedient to God, even though they were still religious (Matthew 15:6-9). In both cases, the people were religious but were not Christians.
  • Doing things for the Lord – In the Sermon on the Mount, Jesus described those who were doing things “in [His] name,” yet they were guilty of practicing “lawlessness” and would not “enter the kingdom of heaven” (Matthew 7:21-23). This means that it is possible to believe in Christ strongly enough to doing various things in an effort to please Him, yet still not be pleasing to the Lord.
  • Being a good person – Cornelius was described as “a devout man and one who feared God with all his household, and gave many alms to the Jewish people and prayed to God continually” (Acts 10:1-2). It would be difficult to find someone who could better fit our concept of a “good” person. Yet even in this condition, Peter still had to come and “speak words to [him] by which [he would] be saved” (Acts 11:13-14).

Of course, we do not want to go to an extreme position and reject these characteristics or say that they do not matter. All of those things are necessary:

  • A Christian must be sincere – Paul told Timothy, “But the goal of our instruction is love from a pure heart and a good conscience and a sincere faith” (1 Timothy 1:5).
  • A Christian must believe in Christ – The Hebrew writer noted, “And without faith it is impossible to please Him, for he who comes to God must believe that He is and that He is a rewarder of those who seek Him” (Hebrews 11:6).
  • A Christian must be religious – When the church was established on the day of Pentecost, it began with an emphasis on collective worship: “They were continually devoting themselves to the apostles’ teaching and to fellowship, to the breaking of bread and to prayer” (Acts 2:42).
  • A Christian must do things for the Lord – Paul wrote, “Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your toil is not in vain in the Lord” (1 Corinthians 15:58). Our service to God must be continuous and always increasing.
  • A Christian must be a good person – Not only that, but we must act in such a way that others notice this. Jesus said, “Let your light shine before men in such a way that they may see your good works, and glorify your Father who is in heaven” (Matthew 5:16).

However, one can be/do these things and not be a Christian. We already noticed some examples of this in the Scriptures. While these characteristics are important and necessary, there is more to determining if one is a Christian than these things.

Be Like Paul

Agrippa recognized that Paul was trying to persuade him to “become a Christian” (Acts 26:28). Paul replied, “I would wish to God, that whether in a short or long time, not only you, but also all who hear me this day, might become such as I am, except for these chains” (Acts 26:29).

Paul wanted to persuade Agrippa (and others) to become what he was. What was Paul? He was what he tried to persuade Agrippa to become – a Christian.

Going back to our question: How can we determine if one is a Christian? We can look at the apostle Paul as an example and see if there are certain steps we can take to become what he was – a Christian.

What did Paul do to become a Christian? Consider the account recorded in the book of Acts (note that he was still known as Saul at this time):

  • He came to believe in Christ – “As he was traveling, it happened that he was approaching Damascus, and suddenly a light from heaven flashed around him; and he fell to the ground and heard a voice saying to him, ‘Saul, Saul, why are you persecuting Me?’ And he said, ‘Who are You, Lord?’ And He said, ‘I am Jesus whom you are persecuting’” (Acts 9:3-5). The fact that he called Jesus Lord indicates that he recognized who He was as the Son of God.
  • He repented of his sins – “And he was three days without sight, and neither ate nor drank. […] And the Lord said to [Ananias], ‘Get up and go to the street called Straight, and inquire at the house of Judas for a man from Tarsus named Saul, for he is praying” (Acts 9:9, 11). His fasting and praying indicated that he was sorrowful for what he had done, had a change of heart, and wanted to be right and do right before the Lord.
  • He was baptized – “And immediately there fell from his eyes something like scales, and he regained his sight, and he got up and was baptized” (Acts 9:18). When he retold his conversion story later, he explained that he was baptized in order to “wash away [his] sins” (Acts 22:16), indicating that his sins had not yet been forgiven despite his penitent heart and fervent prayer to God.

In the chart below, notice the consistent pattern of conversions in the book of Acts. In other words, what Paul did was not unusual – he was told to do what others were told to do in order to become followers of Christ.

Examples of Conversions in the Book of Acts

While not every detail is recorded in each case, each of these steps would have been done by those who were being converted to Christ since the same gospel was being preached in every place (Mark 16:15-16; Galatians 1:6-9). Though not every detail is specified, the details that have been recorded fit within the pattern, rather than being contrary to the pattern; hence the reason why we can call this a consistent pattern.

A note about confession: As can be seen on the chart, a verbal confession was only recorded once in the book of Acts and was not mentioned in the conversion of Saul/Paul. However, we can safely conclude that it was done in each case as it is simply a verbal affirmation of one’s faith. Paul explained, “For with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation” (Romans 10:10).

Who Is a Christian?

Looking at what the New Testament teaches, what should we conclude about who can rightly wear the name of Christian?

  • A Christian is one who has first heard the gospel – “So faith comes from hearing, and hearing by the word of Christ” (Romans 10:17).
  • A Christian is one who has believed in Christ – “Therefore I said to you that you will die in your sins; for unless you believe that I am He, you will die in your sins” (John 8:24).
  • A Christian is one who has repented of his sins – “I tell you, no, but unless you repent, you will all likewise perish” (Luke 13:3, 5).
  • A Christian is one who has confessed his faith – “That if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved; for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation” (Romans 10:9-10).
  • A Christian is one who has been baptized into Christ – “Peter said to them, ‘Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit” (Acts 2:38). “Corresponding to that, baptism now saves you—not the removal of dirt from the flesh, but an appeal to God for a good conscience—through the resurrection of Jesus Christ” (1 Peter 3:21).

Having done those things, a Christian must then live like a Christian. Paul told the brethren in Corinth, “Therefore if anyone is in Christ, he is a new creature” (2 Corinthians 5:17). This means that when one becomes a Christian, he cannot continue to live like the world. Paul explained it to the Romans in this way: “But thanks be to God that though you were slaves of sin, you became obedient from the heart to that form of teaching to which you were committed, and having been freed from sin, you became slaves of righteousness” (Romans 6:17-18). Christians have made a commitment to be obedient to the Lord and live righteous lives in the present world.


The New Testament shows us how to become a Christian. We simply need to do what it says. What the world thinks, or what we think, is irrelevant. Like Agrippa was told, we just need to be such as Paul was – a Christian.

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