The term ‘evangelical‘ is one of the most widely used terms in American culture right now. The popular media uses it to refer to socio-politically conservative people who self-identify as Christian (often synonymous with the term fundamentalist), certain liberal Protestant denominations refer to themselves as evangelicals (perhaps in comparison to their more catholic or high church counterparts), there is a multi-denominational movement stemming from the 1950’s and 60’s originally called Neo-Evangelicalism that was an intellectual and activistic reclamation of Protestantism from the ashes of the modernist versus fundamentalist controversy, and there are many people today (mostly non-denominational) who call themselves evangelical Christians.
In the modern American context, I do believe there is a “right answer” to this question: Evangelical Christianity in America is the descendant of the movement that began about 60 years ago with the likes of Harold Ockenga and Billy Graham, and emphasizes biblical infallibility, biblical literalism, the centrality of Jesus, the penal substitution atonement model, and an emphasis on personal conversion.
But of course the 20th century movement and its present form are just the most recent iterations of Protestant self-identification. One of the first Englishmen (Anglicans) who took on the label of Evangelical was Charles Simeon. In his 1,933rd Sermon, he defined it this way:
As though men needed not to be evangelized now, the term evangelical is used as a term of reproach… It is not our design to enter into any dispute about the use of a term, or to vindicate any particular party, but merely to state, with all the clearness we can, a subject about which everyone ought to have the most accurate and precise ideas…
We have already seen what was the great subject of the apostle’s [Paul’s] preaching, and which he emphatically and exclusively called the gospel, and if only we attend to what he has spoken in the text, we shall see what really constitutes evangelical preaching. The subject of it must be “Christ crucified,” that is, Christ must be set forth as the only foundation of a sinner’s hope, and holiness in all its branches must be enforced, but a sense a Christ’s love in dying for us must be inculcated as the main spring and motive of all our obedience. The manner of setting forth this doctrine must also accord with that of the apostle… in proportion as any persons, in their spirit and in their preaching, accord with the example in the text, they are properly denominated evangelical.
So to him, an evangelical was one preached the gospel of Christ’s death for us sinners, and the call for us to live holy lives in thanksgiving for Christ’s great love for us.
One can see here the germ from which our current Evangelicalism has grown!
Indeed, I think this does represent the heart of the evangelical tradition, in its various forms throughout history and across denominational lines. The emphasis on “preaching it like Paul”, so to speak, links to a network of common assumptions regarding the nature of the atonement in Paul’s writings, the theological understanding of Jesus’ identity, and the secure authority of the Bible to tell us all this in the first place.
In its most basic form, evangelicalism can find a home almost everywhere: in Pentecostalism, in conservative and liberal Protestantism, and even in the Catholic traditions. But taken in its more developed sense of self-identification, it seems to me that Evangelicalism is a generally-conservative form of Protestantism most at home in the Reformed and Baptist traditions, but compatible with Pentecostalism, Lutheranism, and Anglicanism with minor shifts in emphasis.