There are 2 opposed paradigms. Calvinism and Armenianism. Notice they directly oppose on each of the 5 points. Each has a site defending each point in a lengthy statement backed up with scripture references. Notice losing salvation is point 5 of Arminianism. There are both on this site so expect these differences of opinion since all are outside of the creeds. Personally I have a Calvinist aka Reformed viewpoint. Even so I agree to disagree with my fellow Christians the Armenians.
Quinquarticular Controversy
The diametrically opposed Calvinist and Armenian 5 points
Reformed/Calvinism
TULIP
1. Total depravity
2. Unconditional election
3. Limited atonement
4. Irresistible grace
5. Perserverance of the Saints
Armenianism
1. Free will or Human ability
2. Conditional election
3. Universal Redemption or General Atonement
4. The Holy Spirit can be Effectually Resisted
5. Falling from Grace
For a deeper discussion of the differences go to these web sites,
https://www.gotquestions.org/Calvinism-vs-Arminianism.html
Arminianism vs Calvinism Controversial Passages
https://www.xenos.org/essays/calvinism-arminianism-controversial-passages
There are denominations adhering to Calvinism, Arminianism, and parts of each creating a spectrum of different views of these issues.