I remember my downward slide beginning (or was it the first light going off?) when I overheard my then pastor tell someone else "and they show someone
wearing shorts going in the rapture!" -talking about an end time movie being played at the church where someone wearing shorts was... well, you know.
The ludicrousness of someone making a salvation statement about someone who wasn't following the dress code of that church stood out.
The second big light to go off in my head came after hearing a number of men debate "oneness" issues and their understanding of it. Even if I knew what I knew before, I didn't after listening to these guys! They made it virtually impossible to understand
oneness, and yet claimed at the same time that if you didn't understand it like they did, that you were lost.
And the last major big light to go off was comparing the fruits of other Christians to those who I knew to be Pentecostals (UPC) at the time. The bible says you will know them by their fruits. What are the fruits? Love, compassion, long suffering, etc. I was seeing little old catholic nuns showing FAR more fruits then many starch-shirt, stiff collared, pentecostal poof wearing, TV gaze averting, UPCers.
Then I started seeing alllllllll the versus speaking of grace, mercy, faith, and love that I knew were there, but never spent any time on since everything was always steamrolled right to
Acts 2:38.