The phrase "pledge ourselves" is correct and usable in written English.
You can use it when you are making a solemn promise or committing to something. For example: We pledge ourselves to promoting equality and justice for all.
We pledge ourselves not to employ foreign strip-tease artists in our cradle of American burlesque".
We pledge ourselves to serve the people of Australia to the very best of our ability".
We mourn Mr. Milbank's passing and pledge ourselves to the ideals he championed throughout his life.
Let us pledge ourselves to the ideal that the people's will should be heard and heeded.
We pledge ourselves to liberate all our people from the continuing bondage of poverty, deprivation, suffering, gender and other discrimination.
Ever optimistic, heady with love's utopianism, most of us eventually pledge ourselves to unions that will, if successful, far outlast the desire that impelled them into being.
It was a little more than a week ago that we both pledged ourselves to not launching negative campaigns.
Have we not pledged ourselves to the quest for alternative histories, for new ways of seeing and thinking about the world?
On this day, we celebrate our planet's plants and animals while pledging ourselves to combat the ever-present threat of wildlife crime.
The rightful place of health professionals is to renounce the complicity of silence when evil assaults the very thing we have pledged ourselves to protect.
In this diversity, we in India see immense possibilities, and in Sana'a we pledged ourselves to energizing and reviving this semi-dormant organization.
