I think that the historicity of Jesus, exactly as the historicity of e.g. Abraham or Moses, plays no role in this. What's important is the message. It seems to me that you take the whole New Testament as the basis for your assessment of that message which, however, already adds a theological filter to it all. I, for one, don't see much value in anything beyond the four canonical gospels, Book of Revelation, and the Gospel of Thomas.

But yes, if you don't put God-realization (that is to say, self-realization) above everything "worldly" you won't "attain it." And the folks who cling to those "worldly" matters are living in Hell of clinging. Not in the future, but right now. Well, in parlance of the time and place, you can call it God's judgment, but it's not some punishment. It's simple causality. And in the case of Judea in 1st century CE that causality played out as the destruction of Jerusalem when unenlightened ways of Jews clashed with unenlightened ways of Romans.

Furthermore, it's naturally easier for people who have little to cling to to become self-realized, hence, the last will be first in the kingdom of God. But what's most important, uncompromising focus on self-realization is verifiably not relegated to the otherworldly, and definitely not tied to ascetic renunciation, in order to be tenable.

You can try it all for yourself.