God's plan is that man can be saved through the sacrifice of Jesus in the work of the cross and obviously after three thousand years this event occurred God continues to call on humanity to repent of their ways and return to the true path because when man continues to resist and make excuses rejecting the call of God this attitude of rejection will have consequences for humanity.
Zechariah 7:12
And they hardened their hearts like the diamond so as not to hear the law or the words that the LORD of hosts had sent by his Spirit, through the ancient prophets; So great anger came from the LORD of hosts. (RVR1960)
In this verse quoted the prophet tells us about the people who harden their hearts so as not to hear the word of God and close their ears before the call of their hearts rebelling to the eternal God which clears up the prophet will not be challenged because the Lord will be angry , against them also that they will be judged on the day indicated.
John 12:48
He who rejects me and does not receive my words, has a judge; The word that I have spoken will judge that on the final day. (RVR1960)
The gospel of Jesus Christ is being preached throughout the world so that every person can hear of the salvation of his soul and can believe and avoid eternal damnation, because our mission is really to preach and if man rejects the word he has the one who judge in this case it will be our lord Jesus Christ who will one day remind you of those words that they rejected.