My reasons for being a liberal are complex.
I attended a fundamentalist church as a child and it was crystal clear to me that the message Jesus had for all of his flock coincided 100% with the liberal political position. Later in life I learned more about Jewish people and discovered that Jesus's message was very close to the ethical training of Jewish children. No neeed to wonder why--Jesus was a Jewish child. His message, as stated over and over in the new testament, was intended for Jews. It was never conceived (at least as far as I can tell) as a world religion, but as a minor course correction for Judaism.
Follow the law, love God, love your neighbor. What could be simpler or more liberal?
And, holy smokes, recently I've been learning more about Islam, and guess what? It's virtually identical to its brother religions. I've done some examination of religions and I am no longer surprised to hear people espousing a religion I have never heard of, or one I have barely heard of, telling me that the central tenet of their religion is to be peaceful, to love God, to love and care for your neighbor, to find means to cure bad feeling before it becomes a cancer. To care for your parents and the elderly, to care for the orphan and the widow, to care for the halt, the lame, and the sick--essentially to be a liberal in word and deed.
I feel very confident in pronouncing God a liberal and liberalism an appropriate way to worship. Probably better than prayer and sacrifice.
But what if you don't believe in God and have no interest in worshiping in any form? Does that make you a malignant sort of greed-head without morals or ethics? Not in my experience.
Intelligent, rational people who are also atheists or agnostics or heathens or even pagans recognize that there is no percentage in allowing children to starve. If children starve, where will you raise an army, who will be your consumers, your educators, your public servants?
There is no percentage in allowing children to remain ignorant. An ignorant population can't progress and will always be dependent and lagging behind an educated population in all material things (and also spiritual things).
There is no percentage in allowing the elderly to starve or become beggars--we will all be elderly at some point, if we're lucky, and this is not a fate we would choose for ourselves.
It takes no brainiac to recognize that a nation that is wealthy is one that has invested in its children and cared for its poor, ignorant, homeless, sick, and elderly; or to recognize that nations that fail to care for these groups are among the poorest on earth. If you are wealthy in Haiti, you can avoid all income taxes, you can sponge endlessly off the poorest of the poor, force people into slavery, prostitution, or vice in exchange for the promise of a regular meal.
Is this a world anyone would want to live in? People die virtually every day trying to escape this island, which is the realization of the purest form of Reaganomics. Why would anyone risk his life leaving heaven? Clearly, this is hell.
Any time we need to imagine the world as hell, it involves a world under control of a few people with limitless greed, hunger for power, and a complete lack of responsibility and ethics. It's a madness, a disease of the mind.
To be liberal is to be rational. I have been a psychiatric social worker, and I have seen the road psychotics take--and I don't find it attractive, so I side with the rational. Thus, for these many reasons, I am a liberal.