Modern Protestantism?
Most modern day "liberals" worship the creation, not the creator. Or they worship such cults as "climate change", or "government."
Intellectual liberty and the spiritual and ethical content of Christianity?
Come on, really? Modern-day American liberalism leans more toward Marxism and socialism, than anything else. Liberals believe in the redistribution of wealth, anti-capitalism, and secular collectivism.
A theory in economics emphasizing individual freedom from restraint and usually based on free competition, the self-regulating market, and the gold standard
Actually, modern-day American liberals are responsible for the restraints, burdensome regulations, high taxes and other forms of interference from the government.
A political philosophy based on belief in progress, the essential goodness of the human race, and the autonomy of the individual and standing for the protection of political and civil liberties.
This one is hilarious. Progressives view themselves as "enlightened" social reformers, apart from the ignorant and unwashed masses. They are so far left, they don't even like the liberals. They have absolutely no tolerance for individuality, the rights of those outside their political sphere, and are the ones who invented "cancel culture."