Theological liberalism (as J. Gresham Machen described it so well) is anything that seeks to tame Christianity and use it for its own purposes.
It can take the form of the social gospel, where Jesus becomes little more than a means to relieving poverty and oppression, things that are certainly good, but Christless and gospel-less when you remove the cross and the necessity of conversion.
It can take the form of the prosperity gospel, where God is simply a means for the realization of my health and wealth — a cosmic vending machine if you will; a genie to grant me my selfish desires.
It can take the form of so much of what goes on in mainline evangelicalism, where sermons are no more than pop psychology lessons cast in Christianese, where Christianity is “Life in the Suburbs 2.0,” here to make your life a little bit more comfortable and functional.
And it can take the form of the Religious Right, where particular political ideologies and agendas get baptized as Christian, where appeals to faith are shallow attempts to mobilize Christians as political allies, and where scripture gets abused (think “people of God” texts for [insert United States here]) are used for one’s own end and as ammunition in a misguided expression of culture war.
On the other hand is a theological conservatism: Jesus does not exist for my purposes; I exist for his.