What was the main theme of Christ's message?
"Now after John was put in prison, Jesus came to Galilee, preaching the gospel of the kingdom of God" (Mark 1:14).
"Now it came to pass, afterward, that He went through every city and village, preaching and bringing the glad tidings of the kingdom of God. And the twelve were with Him" (Luke 8:1).
From the beginning of Christ's earthly ministry, He focused on the Kingdom of God. He was continuing the message proclaimed by Daniel and the other prophets. Throughout His ministry He repeatedly used the words king and kingdom to explain the good news He preached.
What other theme was prominent in Christ preaching?
"The time is fulfilled, and the kingdom of God is at hand. Repent, and believe in the gospel" (Mark 1:15; compare Matthew 9:13).
Jesus taught that no one can enter the Kingdom of God unless he repents: "Not everyone who says to Me, 'Lord, Lord,' shall enter the kingdom of heaven, but he who does the will of My Father in heaven. Many will say to Me in that day, 'Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?' And then I will declare to them, 'I never knew you; depart from Me, you who practice lawlessness!'" (Matthew 7:21-23; compare Matthew 19:16-17; 1 John 2:4).
Obeying Jesus Christ is different from simply believing in Him. Submitting to God's will requires a change of heart. It means we come to trust God and willingly repent of sin, which is lawlessness (1 John 3:4), the breaking of God's law. Here is where many sincere people misunderstand not only the gospel but what one must do to enter God's Kingdom and receive His gift of eternal life.
Our faith in God and in the reliability of His promises must lead to a life of active obedience. Otherwise our faith is dead and useless (James 2:26).
What did Jesus say is necessary for someone to enter God's Kingdom and receive eternal life?
". . . One came and said to Him, 'Good Teacher, what good thing shall I do that I may have eternal life?' So He said to him, 'Why do you call Me good? No one is good but One, that is, God. But if you want to enter into life, keep the commandments'" (Matthew 19:16-17).
What message was uppermost on Jesus Christ's mind after His resurrection?
"To [the apostles] He also presented Himself alive after His suffering . . . being seen by them during forty days and speaking of the things pertaining to the kingdom of God" (Acts 1:3).
After explaining more details of the gospel of the Kingdom of God, Jesus sent His apostles out into the world to teach the nations those truths (Acts 1:8; compare Matthew 28:19-20).