Evangelism, the communication of the gospel message, includes a warning, an explanation, and a call. Evangelism includes warning people about sin and the consequences of sin.

John 16:8;

 When he comes, he will prove the world to be in the wrong about sin and righteousness and judgment

Acts 24:25;

As Paul talked about righteousness, self-control and the judgment to come, Felix was afraid and said, “That’s enough for now! You may leave. When I find it convenient, I will send for you.”

Revelation 20:11-15;

¹¹ Then I saw a great white throne and him who was seated on it. The earth and the heavens fled from his presence, and there was no place for them.¹² And I saw the dead, great and small, standing before the throne, and books were opened. Another book was opened, which is the book of life. The dead were judged according to what they had done as recorded in the books.¹³ The sea gave up the dead that were in it, and death and Hades gave up the dead that were in them, and each person was judged according to what they had done.¹⁴ Then death and Hades were thrown into the lake of fire. The lake of fire is the second death.¹⁵ Anyone whose name was not found written in the book of life was thrown into the lake of fire.

It includes an explanation of God’s remedy for sin-the gospel

Acts 8:29-35;

²⁹ The Spirit told Philip, “Go to that chariot and stay near it.”

³⁰ Then Philip ran up to the chariot and heard the man reading Isaiah the prophet. “Do you understand what you are reading?” Philip asked.

³¹ “How can I,” he said, “unless someone explains it to me?” So he invited Philip to come up and sit with him.

³² This is the passage of Scripture the eunuch was reading:

“He was led like a sheep to the slaughter,
    and as a lamb before its shearer is silent,
    so he did not open his mouth.³³ In his humiliation he was deprived of justice.
    Who can speak of his descendants?
    For his life was taken from the earth.”^[a]

³⁴ The eunuch asked Philip, “Tell me, please, who is the prophet talking about, himself or someone else?”³⁵ Then Philip began with that very passage of Scripture and told him the good news about Jesus.

Romans 3:21-26;

²¹ But now apart from the law the righteousness of God has been made known, to which the Law and the Prophets testify.²² This righteousness is given through faith in^[a] Jesus Christ to all who believe. There is no difference between Jew and Gentile,²³ for all have sinned and fall short of the glory of God,²⁴ and all are justified freely by his grace through the redemption that came by Christ Jesus.²⁵ God presented Christ as a sacrifice of atonement,^[b] through the shedding of his blood—to be received by faith. He did this to demonstrate his righteousness, because in his forbearance he had left the sins committed beforehand unpunished—²⁶ he did it to demonstrate his righteousness at the present time, so as to be just and the one who justifies those who have faith in Jesus.

2 Corinthians 5:21;

God made him who had no sin to be sin^[a] for us, so that in him we might become the righteousness of God.

And it includes the clear call to repent (to turn from sin and to turn toward God) and believe the gospel, by faith.

Mark 1:15;

“The time has come,” he said. “The kingdom of God has come near. Repent and believe the good news!”

Luke 13:1-5;

Now there were some present at that time who told Jesus about the Galileans whose blood Pilate had mixed with their sacrifices.² Jesus answered, “Do you think that these Galileans were worse sinners than all the other Galileans because they suffered this way?³ I tell you, no! But unless you repent, you too will all perish.⁴ Or those eighteen who died when the tower in Siloam fell on them—do you think they were more guilty than all the others living in Jerusalem?⁵ I tell you, no! But unless you repent, you too will all perish.”

Acts 17:29-31;

²⁹ “Therefore since we are God’s offspring, we should not think that the divine being is like gold or silver or stone—an image made by human design and skill.³⁰ In the past God overlooked such ignorance, but now he commands all people everywhere to repent.³¹ For he has set a day when he will judge the world with justice by the man he has appointed. He has given proof of this to everyone by raising him from the dead.”

Romans 1:17;

For in the gospel the righteousness of God is revealed—a righteousness that is by faith from first to last,^[a] just as it is written: “The righteous will live by faith.”

Romans 10:9-13;

⁹ If you declare with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved.¹⁰ For it is with your heart that you believe and are justified, and it is with your mouth that you profess your faith and are saved.¹¹ As Scripture says, “Anyone who believes in him will never be put to shame.”^[a]12 For there is no difference between Jew and Gentile—the same Lord is Lord of all and richly blesses all who call on him,¹³ for, “Everyone who calls on the name of the Lord will be saved.”