Heaven does not appear until after the resurrection of Jesus and some other changes; Satan thrown from Heaven. The Jews of the Old Testament did not have a heaven and hell. So when Luke is quoting Jesus, when Jesus was still preaching, heaven and hell did yet not exist. Abraham was sleeping and would awaken from his sleep many generations later.
Both those quotes really have to do with being able to develop your mind; spirit, from either the outside or from the inside. If you had lots of money, you can hire others to do everything for you. You can create the illusion of being a master of everything that money can buy, while not knowing how to do anything, besides buy and delegate. Others will be impressed by your shiny shell and not notice how there is nothing inside, just an impressive shell they envy.
On the other hand, the poor person who has little, has to learn to do everything for themselves, even the simple things that money could buy. That need requires they develop from the inside, by trial and error and hard work; blessed are the poor. Born again was about developing the inner man; genuine change, and letting the outer man, that money can buy, die away; new suit or hair style, so there is real inner change and not store just bought outer change.
If I had plenty of money I could buy designer clothes to make me look rich and state of the art. If I have no money, I would need learn how to make my own clothes. Which takes more skill, but which will the mob gravitate towards? Narrow is the way and few people see it. If you develop from the inside, there is less need to make war to feed the dark inner hole. Historically, many go the rich tended to regress into debauchery since the inside was empty and needed new stimulus to feel. The path to the Kingdom of Heaven was though the inside; prayer, meditation and faith, not appealing to the outer mob to be seen or feared.