Protestantism: The branch of Christianity that emerged from the 16th-century Reformation, rejecting certain Roman Catholic doctrines and practices and affirming the principles of salvation by faith alone, the priesthood of all believers, and the Bible as the sole source of revealed truth.
Ecumenical Movement: A movement among Christian churches and denominations to promote cooperation and unity, often working towards the goal of achieving a united or universal Christian church.
Theological Liberalism: A approach to Christian theology that emphasizes the importance of individual reason and experience over strict adherence to traditional doctrines, often embracing a more progressive interpretation of scripture and religious beliefs.