The Bible reveals in the gospels that the kingdom is the crowning message we are to proclaim. Salvation should not be presented as the end goal. Inheriting the kingdom should be. Salvation is the means to the kingdom. The king wants the big picture of the kingdom revealed first to give us a prize to run after. Luke 4:43, & 13:18-20, Mark 4:8, Revelation 3:21. Hebrews 12:1 says we have a race to run with an audience cheering us on. "this gospel of the kingdom" in Matthew 24:14, is directly connected to the great commission. It was the last message Jesus gave to his disciples just moments before he ascended into Heaven. You may be saved from destruction but there is no good news of the Kingdom for you if you are not taking part in the expansion of it! Therefore go into all the world and make disciples of all nations... Matthew 28:19

If you are not spreading the good news of the kingdom by participating in some way to make disciples of all nations (promoting the knowledge of God by turning the few minas God gave you into many Luke 19:11-27 ) you will not inherit the rewards of the kingdom. You may have some treasures in Heaven but you will not inherit the kingdom. If you believe in Jesus Christ you are called to participate. But if you do not participate, you simply are not living a full gospel life. You are living in    1 Corinthians 3:14 salvation. The thief on the cross was saved but did he have an inheritance in the kingdom? A lot of Christians don't understand this and that is why the gospel is referred to as a "mystery".

The gospel of the kingdom is about the salvation of the nations. That is the gospel we are called to preach first not "the gospel of your salvation" Ephesians 1:13. You can have salvation without inheriting the kingdom but you cannot inherit the kingdom without having salvation. Without the kingdom you will have a gown of salvation but not be arrayed in a robe of righteousness. Isaiah 61:10. The message of the kingdom is all about the expansion of it and your participation. Look at the kingdom parables in Matthew 13. They are all concerning different aspects of evangelistic work. They reveal 7 different ways the kingdom is established; scattering, planting, growing, mixing, discovering, evaluating & separating. 

When you keep the greatest commandment first, Mark 12:30, Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength, you will naturally follow with the second greatest commandment. "Love your neighbor as yourself" Which is to fulfill the great commission, but people seem to think the second greatest commandment is not really a commandment but a great suggestion. Not true. Jesus said if you love me you will obey my commands. John 14:15. Loving your neighbor as yourself is tied to fulfilling the great commission.

When you look closely at the parable of the minas you will see that God expects a return on his investment in you. Luke 19:11-27. Is it really money (minas) that God is expecting you to multiply?  Not necessarily. It is the expansion of the kingdom by using whatever resources God has given you to making disciples of all nations. The servant who didn't produce a return was rebuked and demoted. Has God given you some minas you can put to work? If you are not doing kingdom work directly yourself then you should be supporting others who do. I believe that is what is meant in Luke 19:23 'Why then didn’t you put my money on deposit, so that when I came back, I could have collected it with interest?’