Christians, in Luke 8:1, Jesus is preaching the gospel of the kingdom of God. Since he had not yet been crucified, what was his message?

The author of Luke has much to say on the subject.

Perhaps this passage is the most descriptive (but it is not the only passage describing in Luke the kingdom of God, nor is this chapter provide a complete description).

https://www.biblegateway.com/passage/?search=luk+1...

Clearly "the kingdom of God" refers to eternal salvation. This interpretation is buoyed by such teachings as this:

https://www.biblegateway.com/passage/?search=luk+1...

Preparatory work. Jesus is the KING of the Kingdom, bringing joy and hope to poor, oppressed ppl.

That sure answer is God’s kingdom. This kingdom is a real government, with a heavenly king and with earthly subjects.

Jesus’ earthly life as a grown man was devoted to declaring that government as the only solution to man’s problems. Luke 4:43; 8:1

How it will eliminate crime is clearly shown in the Bible.

God’s heavenly kingdom or government will completely destroy earth’s present governments, with all their crime and corruption.

this system of things is irreformable; it is permeated with crime.

Its ruler is Satan the Devil, who is misleading the entire inhabited earth. Mankind cannot get rid of him; only God can.

Thus Jesus taught us to pray for God’s kingdom to come so that it might crush Satan and his crime-infested system out of existence. Matt. 6:9, 10

Jesus never ministered to any "Christians"...... The Commission Jesus' Father, The Creator God, Gave him, was to minister to The Nation of Israel.... those of The Nation of Israel had gone off The Way God had set for them.... Jesus was to bring them back to The Way they were supposed to go...... Jesus taught only The Word and Will of his Father for The Nation of Israel......................... After Jesus Ascended into Heaven, God commissioned The True Church.... Jesus' Apostles were the first ministers of The True Church... they carried The Word and Will of God, for His Church, to the world.... much of what was taught by Jesus to The Nation of Israel was carried over in the instructions to The True Church