The entire gospel message hinges on who Jesus Christ is. Many people believe He was a teacher, a prophet, but don't believe He is God the Son. When we take our final breath, who we believe Jesus to be determines our eternal dwelling place. The only way anyone can get to heaven is by believing in Jesus as the Savior and Lord.
Peter and John approached the Temple Gate called the Beautiful Gate and saw a crippled man who had been that way from birth. Through the power of Jesus, Peter healed this man. His bones snapped into place and he was made strong. He was supernaturally given the ability to function normally. He was someone who had never walked, run, or jumped. Yet, through the power of the Holy Spirit, he was able to do so.
When he followed Peter and John into the temple, he didn't do so quietly. People would have recognized him.
Acts 3:10 tells us how they responded, "And they were filled with wonder and amazement at what had happened to him."
Verse 11 goes on to say, "While he clung to Peter and John, all the people, utterly astounded, ran together to them in the portico called Solomon's."
Now, he wasn't clinging onto Peter and John because he was having a difficult time walking. He clung to Peter and John for two reasons: gratitude and shock.
Peter began his sermon in verse 12 with these words: "Men of Israel, why do you wonder at this, or why do you stare at us, as though by our own power or piety we have made him walk?"
Do you see what Peter did here? He began his sermon by deflecting the glory away from himself and John. We should have the same attitude when God uses us to accomplish something in someone else's life.
Isaiah 64:8 says, "But now, O LORD, you are our Father; we are the clay, and you are our potter; we are all the work of your hand."
The pot cannot take credit for anything the potter does. In the same way, we are to point others to Jesus and give Him all the credit.
So, how do we humble ourselves and elevate Christ?
First, we must tell people who Jesus is.
Peter did this by referring to numerous titles that apply to Jesus:
- Verse 13: The God of Abraham, the God of Isaac, and the God of Jacob
- Verse 13: God's Servant
- This reference is from Isaiah 52-53, where the prophet predicted this servant, the Messiah, would be "pierced through for our transgressions" and that the Lord would cause "the iniquity of us all to fall on Him."
- Verse 14: The Holy and Righteous One
- Here, Peter exalted Jesus as God. He said Jesus was without any sin of His own. Since the only way to be holy and righteous requires sinlessness, and since God is the only One who is sinless, Peter was calling Jesus God.
- Verse 15: The Author of Life
- Verses 18 and 20: The Christ Appointed by the Father
- This means Jesus didn't appoint Himself as the Messiah. God the Father appointed and anointed Him, fulfilling many Old Testament Messianic prophecies.
- Verse 22: The Prophet Moses Predicted
- Verse 25: The seed of Abraham (through whom all the nations of the earth would be blessed)
It is all summarized in verse 16, where Peter says, "And his name—by faith in his name—has made this man strong whom you see and know, and the faith that is through Jesus has given the man this perfect health in the presence of you all."
The name of Jesus means everything. It encompasses everything He is.
When we share the gospel with others, we must always bring them face to face with who Jesus is, the Savior and Lord, God Himself.
We must also tell them what He did.
Acts 3:13 says, "The God of Abraham, the God of Isaac, and the God of Jacob, the God of our fathers, glorified his servant Jesus, whom you delivered over and denied in the presence of Pilate, when he had decided to release him. But you denied the Holy and Righteous One, and asked for a murderer to be granted to you, and you killed the Author of life, whom God raised from the dead. To this we are witnesses
Jesus laid down His life willingly, as punishment for our sins. The cross of Christ must be the central feature of our witness.
First Corinthians 1:18 says, "For the word of the cross is folly to those who are perishing, but to us who are being saved it is the power of God."
Acts 3:15 says, "And you killed the Author of life, whom God raised from the dead. To this we are witnesses."
So, where was this risen Messiah?
Peter explained in verse 21, "Jesus, whom heaven must receive until the time for restoring all the things about which God spoke by the mouth of his holy prophets long ago."
Jesus ascended into heaven, but He will return one day—and destroy all who do not believe (verse 23). He will make all things new.
Not only must we tell people who Jesus is and what He did but also warn them of the consequences of sin. Warn Sinners of Judgment
Peter was forthright about the consequences of sin. He also told listeners Jesus's crucifixion and resurrection were predestined by God. But even though God predestined every detail, we are still responsible for our sin.
We must understand that we've all sinned, that we all deserve eternal punishment. Otherwise, why would Jesus have had to die in our place?
He died on the cross for sinners under God's wrath and judgment. Jesus died on the cross because, without a perfect sacrifice to cover those sins, we would all rightfully go to hell.
Even though Peter's message was calling out the Jews sin of killing their Messiah, theologian Charles Spurgeon says, "Every sin in the essence of it is a killing of God" 
If we've never trusted in Christ as Savior and Lord, we're no different than the crowd before Pilate, choosing a murderer over the Lord.
Peter was calling out the sins of the people because he knew the only hope for anyone was forgiveness through Jesus Christ.
Ephesians 2:11-12 says, "Therefore remember that at one time you Gentiles in the flesh, called "the uncircumcision" by what is called the circumcision, which is made in the flesh by hands— remember that you were at that time separated from Christ, alienated from the commonwealth of Israel and strangers to the covenants of promise, having no hope and without God in the world."
When someone is lost, they're without God and have no hope. All stand guilty and condemned before God. Yet, when we share the gospel with people, lovingly calling out sin, it opens the door for the hope of Christ.
When we share the gospel, we must not only tell people who Jesus is and what He has done. We must not stop at telling them about the consequences of their sinfulness. We must go on to offer them God's grace. Offer God's Grace to Those Who Repent
Acts 3:19 says, "Repent therefore, and turn back, that your sins may be blotted out."
Even though they were responsible for killing Jesus, if they would repent of their sins, God would forgive them.
How did the people respond to Peter's call to repent? Two thousand people trusted in Christ as Savior and Lord.
This is astounding! Peter preached a sermon that indicted the crowd. He not only accused them of murder, but said they were all guilty. Still, he told them, God offered them forgiveness. Mind-blowing!
He offers this same forgiveness to all who repent.
So, what is repentance? It's turning away from a life of sin and turning to Jesus as Savior and Lord.
Spurgeon said, "Repentance is to leave the sins we loved before, and show that we in earnest grieve, by doing so no more" 
Let's share all these truths with unbelievers.
 Metropolitan Tabernacle Pulpit [Ages Software], vol. 14, "Apostolic Exhortation," on Acts 3:19