Having spent over a year as a “non-denominational evangelical Christian Fellowship” I have seen a few approaches.
We had one Pastor who held to an Arminian theology somewhat, somehow he held to OSAS, just not logically
The Assistant Pastor was a Calvinist, so Obviously OSAS was espoused
Most of the Congregation believed you could walk away from Salvation, which meant, by your Actions (denied works of course) or one could lose faith (Apostacy) or by your works it shows that you have lost faith

Each group all held to the notion that the Holy Spirit was Removed from them, Left them, or they Lost the Holy Spirit
All these different views were in a group no bigger than 40 people (very small Calvary Chapel)
The head Pastor would say, that “as a believer you can fall anywhere on the boat, but never fall overboard, because God built the walls to high”

His view was that people that fall into “major sin” repeatedly, like drug addicts, alcoholics, etc may have “been saved” at a point in their lives, but it’s unlikely, and any fruit that they seemed to bear was a human work, not God’s. He believed that people could come close to receiving the Holy Spirit, but not receive Him, because they didn’t Repent and trust Jesus enough to receive Him

A product of a type of** quality of faith, or Saving Faith**! He said that, we were NOT called to be judges, but we were called to be fruit inspectors!
I was speaking with a man that had a problem with drug addiction, (I struggled with alcohol for years) And was trying to offer some advice. The assistant Pastor afterwards told me, that “I am wasting my time” That this guy “says he had received the Lord, but it’s obvious he has not, being that the word says He who starts a good work in you will complete it” I wonder if the assistant Pastor questions his own salvation, every time he falls into “serious sin”
Others in the Congregation would say that they received Christ one sunday when they were moved by the Holy Spirit, and said the sinners prayer

,but then fell away, and went back into the world. In doing so they Lost, had Removed, or walked away from the Holy Spirit, by sinning, or by a loss of faith, or by doing wrong, it was showing that they didn’t really and truly believe, or believe enough, (
have a type of saving faith or quality of faith) Or their actions were bearing witness that they had Lost, walked away from, or had removed from them, the Holy Spirit

Most of them end up "
rededicating" themselves to the Lord, and in doing so, once again receive the Holy Spirit’s indwelling again. Funny,** they would never use the term I got born again, again.**
I don’t know if any of you are familiar with Shane Claiborne, but years ago I listened to him talk, jokingly, about how he got born again, and again, and again, and again, every year at a revival camp through baptism!
All of the groups I had mentioned were adamant about how
you can KNOW you are saved. 
and that almost all
Catholics are Lost
95% of them identify themselves as “ex-catholics” that were “saved” out of religion and now have a personal relationship with Jesus Christ, and listened to a vehemently anti-catholic Pastor preach week in and week out!
I thank God for a sacramental economy
The biggest reason for the hated of the Catholic Church from these people, was emotional! They would say look at the people, they go to the Catholic Church on sunday, and live like the devil on monday!
I never had that, being that the greatest witnesses in my life for Christ were Catholic.
Reverted back to the Church 2 years ago, and it still feels sooooooooooo good to be Home!