You can’t beat people over the head with a book or scare the pants off them with fiery preaching and expect them to “love” God.
In the Middle Ages that way of teaching was more effective, because most people were illiterate and under-educated. Today, people are better educated and able to read religious texts themselves.
And because of the Scientific Revolution, we have a much better understanding of how the natural world works.
Today, people are also much less likely to obey authority. Including religious authority, because we’ve embraced the values of democracy. Religion thrives on autocracy and tends to have very little tolerance for those who think for themselves.
When we relate to God from the perspective of connection, instead of obedience to a harsh judge, love for God becomes possible.