Evangelicals are protestants who believe in the mission to spread the Gospel in everything they do. They meet a lot of resistance and are hated for intruding into the spiritual zone of society where ostensibly they were never invited. But they reason that if they are able to turn people to Christ, even one soul, then it is worth it, it is victory.
Evangelicalism is important in the political sphere because it is a force that holds society to account.
Any standard text on Theology will brief you on the evolution of the various Protestant sects. It’s not that difficult and the various factions are simply a reflection of the war that goes on inside each human soul. Same with Catholics that we see today. The Orthodox are also splintered, but at least, their Divine Liturgy is unchanged for nearly 2000 years, although they argue and quibble stupidly outside the Church at times.
If you’re frustrated, then you might consider liberalism which posits that to solve the human problem, all that is necessary is to destroy humanity. There you have it.
Good luck.
Last count, IIRC, there were something on the order of 20,000+ Protestant denominations - each being a splinter group situation (The price of “personal interpretation” of scripture?)
We Catholics have a civil war brewing in the Church, between the traditionalists (orthodox) and the modernists (liberal, Post Vatican II, novus ordo, etc.) The sodomites and Marxist have taken over the Church (thanks to the intrigue of Freemasonry and Communism) ... With Francis (Jorge Bergoglio) as Pope, all hell is breaking loose, as he speaks one heretical absurdity after another - it is becoming an intolerable situation for many Catholics - even the liberals are beginning to get nervous.
Insofar as no change to the liturgy in 2000 years ... if only it were so! Despite the prohibition (on pain of suffering the penalty of “anathema,” for violation of the papal bull (constitution / law), Quo Primum, enacted by Pope Saint Pious V against altering the Sacred Liturgy of the Mass ... The “innovators” (liberals) and periti (experts) of Vatican II did in fact alter the liturgy, beginning in 1962 ... to the point where by 1970 the Catholic Mass was no longer recognizable as such, and was more Anglican in form.
http://catholicapologetics.info/modernproblems/newmass/qprimum.htm