Charles G. Finney was a key figure in the Second Great Awakening, a revival movement that is in some sense the backbone of the evangelical movement in the US until this day. His Lectures on Revivals of Religion (pdf) are a theological attempt to address some of the concepts of the revival movement.
He argued that
God has established no particular system of measures to be employed and invariably adhered to in promoting religion.
…
It is preaching the Gospel that stands out prominently there as the great thing. The form is left out of the question.
Finney argues that dress, worship styles and music performance are all examples of manmade structures, and strangely his observation is as relevant to the church today as it was almost two hundred years ago. When organs came to the church,
They would not be half so much excited to be told that sinners are going to hell, as to be told that there is going to be an organ in the meeting house. … They act as if they had a “Thus saith the Lord” for every custom and practice that has been handed down to them, or that they have long followed themselves, however absurd or injurious.
He addresses the issue of lay ministry and how the establishment is weary, giving away the meant tasks of the ministers.
It used to be said that for a layman to pray in public, was interfering with the dignity of ministers, and was not to be tolerated. A minister in Pennsylvania told me that, a few years ago, he appointed a prayer meeting in the church, and the elders opposed it and turned it out of the house. They said they would not have such work, they had hired a minister to do the praying, and he should do it, and they were not going to have common men praying.
According to Finney,
it has been in regard to all the active movements of the church. Missions, Sunday Schools, and everything of the kind, have been opposed, and have gained their present hold in the church only by a succession of struggles and a series of innovations.
He is critical of seminary education, claiming it can hinder innovation and experimentation. There is a similar sense in the finding of NCD (Natural Church Development), indicating that there is a negative correlation between education of the church leaders and the vitality of the congregation. Finney says:
If ministers will not go forward, and will not preach the Gospel with power and earnestness, and will not turn out of their tracks to do anything new for the purpose of saving souls, they will grieve the Holy Spirit away, and God will visit them with his curse, and raise up other ministers to do his work in the world.