Why it makes a practical difference whether we preach the Gospel of the Kingdom of God or the going to Heaven when we die?
When people are taught that their goal is to escape Hell and go to Heaven when they die, and their ticket is divine grace and their conduct is not a critical part of their salvation, and given the demonic pressure that is on us, what do you think is going to happen?
The result is going to be believers who are easily overcome by Satan.
The Gospel of the Kingdom is not like this. It goes to work every day, challenging us to take a step further into the Kingdom of God by gaining victory over worldliness, lust, and self-will. Entering the Kingdom of God is something we do now, not a hope concerning when we die.