In my opinion... the vast majority of denominations (UPCI included) are rampant with pagan and/or reformist influence be it doctrinal, structural, or traditional.
Guys... even the beloved "sermon" is pagan. The early Sophists perfected Platonic rhetoric with a monologue that comprised of an opening, text/preposition, and at least four supplimental points, and a closing. The very structure of most sermons is... pagan.
Biblically speaking when Christians gathered, they gathered in smaller groups. There was a reading, some hymns, and open discussion with regards to the Scriptures or the life of Jesus. All "preaching" was discussion based or extemporaneous, led by the Spirit.
Paul tells us what a meeting should be like:
I Corinthians 14:29-38
29 Two or three prophets should speak, and the others should weigh carefully what is said. 30 And if a revelation comes to someone who is sitting down, the first speaker should stop. 31 For you can all prophesy in turn so that everyone may be instructed and encouraged. 32 The spirits of prophets are subject to the control of prophets. 33 For God is not a God of disorder but of peace—as in all the congregations of the Lord’s people.
34 Women should remain silent in the churches. They are not allowed to speak, but must be in submission, as the law says. 35 If they want to inquire about something, they should ask their own husbands at home; for it is disgraceful for a woman to speak in the church.
36 Or did the word of God originate with you? Or are you the only people it has reached? 37 If anyone thinks they are a prophet or otherwise gifted by the Spirit, let them acknowledge that what I am writing to you is the Lord’s command. 38 But if anyone ignores this, they will themselves be ignored.
Now, that's a BIBLICAL gathering.