Non-existent kingdom??? So Jesus was jiving us when He said, “And as ye go, preach, saying, The kingdom of heaven is at hand.”
And we are to witness to what?...the ineffectiveness of God and his power to transform men? and cultures? Doesn’t obedience to God and His law bring about blessings that are tangible?
And yes, salvation first and then living an obedient life in God's will can bring tangible blessings.
And the "Kingdom of God" is at hand as we can see by the end-time prophecies being fulfilled almost on an hourly basis in our generation. As Christians we have a responsibility to spread the Gospel and make as many people as possible aware that Christ is returning soon to, among other things, set up His kingdom.
But nowhere does Jesus say that there will be a literal, physical kingdom set up by human beings and nowhere does Jesus say that we are to work to gain control of the earth's governments and social institutions. Nor does Jesus' return depend on human beings attempting to do any of those things.