How Important is it To Know Non baptist theologies/beliefs?

For my purposes, there are three general types of Arminians excluding cults and the RCC. I am sure there are other classifications to group Arminians.

The Classic Arminians believe that a True Christian can forfeit his salvation by deciding to stop trusting Christ. This is the only way his salvation can be affected. There are variations within this group.

The Wesleyan Arminians believe a True Christian can lose his salvation while still believing, by long time resistance of the conviction of the Holy Spirit concerning known sins. Again, there are variations within this group.

Then there are some Holiness groups that tend to call themselves Wesleyan Arminians, but put various and excessive emphasis on sanctification. For instance, some Holiness groups believe Christ is crucified again each time we sin.

A quote from anyone within any of the Arminian groups should not be taken to reflect what other Arminians believe.

 

Yes of course everyone seems to agree it is important to know these things in order to confront error.

Granted - however the one practice offering the greatest guarantee of detecting and confronting error of any kind is to be mighty in the scriptures.

Acts 4

24 And a certain Jew named Apollos, born at Alexandria, an eloquent man, and mighty in the scriptures, came to Ephesus.
25 This man was instructed in the way of the Lord; and being fervent in the spirit, he spake and taught diligently the things of the Lord, knowing only the baptism of John.
26 And he began to speak boldly in the synagogue: whom when Aquila and Priscilla had heard, they took him unto them, and expounded unto him the way of God more perfectly.
27 And when he was disposed to pass into Achaia, the brethren wrote, exhorting the disciples to receive him: who, when he was come, helped them much which had believed through grace:
28 For he mightily convinced the Jews, and that publickly, shewing by the scriptures that Jesus was Christ.​

HankD​

 

This thread has already spun off into a debate about this or that, which I expected when I read the title, but back to the OP question:

Yes! By all means. And not just other "denominations" but also the beliefs of the cults, philosophies, and "isms".

How can we correctly (without coming off like a bunch of pompous back-sides) approach persons from these other worldviews unless we know something of what they teach and believe?

"Knowing" is not the same as "following" or "believing" and we should exercise our minds to know. Same goes for evolution and other science-based issues, doctrines and their stance within (and without) the body, and also historical theology so that we can know when we see repeated heresies.

 

IN general, all three divisions believe some form of free will is required to become a part of God's elect. The one difference that I know of, would be the Lutherans who believe in unconditional election for becoming a Chistian; however, they believe one can then forfeit their salvation by deciding to then reject salvation, such as being converted to the Muslim religion.

Concerning corporate election, most believe in corporate election, but not individual election.

There may be other beliefs variations that I don't know of. A few years ago, I did a study of what other denominations believe, but my study was limited.

 

It would also be helpful to know what they think we believe. For instance, if we say eternal security, do they know which version of eternal security we are referring to?