What reasons do those who reject the JEPD view of Scripture provide?

One statement of the JEPD theory is that the "Jahwist" author wrote passages where Jehovah is used, and the "Elohist" wrote passages where Elohim was used, and then later a redactor merged two separate documents in certain sections of the Torah.

While this may be ignored by most Christian churches which take the position of a single author for each book, the theory is seen as unlikely, simplistic, or only partially true in the New Church, which is based on scripture and the revelations given to Emanuel Swedenborg. The New Church considers that Moses composed much of the Torah, but also that certain passages were based on an earlier book known as the book of Jasher (see Apocalypse Revealed, by Swedenborg, n. 11).

The JEPD theory, which proposes that separate Jahwist and Elohist passages were merged together, is considered to be a mistake because JEPD scholars missed the point that the author(s) of the Torah used a form of Hebrew parallelism in structuring prose sections of the Torah. Hebrew parallelism is a form of poetry most evident in the Psalms where alternating lines will repeat themselves in a slightly different manner. In Hebrew parallelism, it is intentional to have repeating lines in poetry, and JEPD theory has missed the point that Hebrew parallelism is also used in prose passages in the Torah.

Before the JEPD theory was formulated in the 19th century, in the mid-18th century Swedenborg published an extensive multi-volume work, Heavenly Arcana (aka Arcana Coelestia) which explained the spiritual meaning behind the literal sense of Genesis and Exodus. In the explanation, it is shown that the parallel passages which alternate between using Jehovah and Elohim are not accidental but quite intentional. The hidden spiritual meaning is that Jehovah is used to refer to the "Divine love," and Elohim is used to refer to "Divine truth." Passage after passage alternates between talking about love and truth, but this is not always apparent in the literal sense of the words.

So while in the New Church the JEPD theory regarding "Jahwist" and "Elohist" passages is seen as failing to recognize Hebrew parallelism in the Torah, this does not necessarily mean that the theories regarding the "Priestly" and "Deuteronomist" passages are considered incorrect. In the New Church there is no requirement for any book of scripture to have a single author - the only requirement for a work to be considered Divinely inspired is that the literal words must have a higher or internal spiritual meaning.

I don't think that it is a matter of "limiting" God. I guess I've never heard anyone say that the theory is invalid because it "limits God".

The primary reason for rejecting the view is, for many, simply a matter of the traditional method of understanding Scripture, and it's origins.

Put simply (perhaps too simply), it is more likely that the people who actually lived in ancient times and lived through the events of those times had a better understanding of those times and the events of those times than someone who lived hundreds of years later.

Based on that reasoning, it's simply more plausible to accept the traditional view of the authorship of the Pentateuch than it is to believe a theory derived hundreds of years after the fact.

Whether the tradition started at the time of Moses, with those who were actually in the wilderness with him, or if the authorship was attributed to him later, the argument still remains that Mosaic authorship had been accepted by those who were much closer in time to the actual events than the later critics.

Another reason for rejecting the theory include the fact that it is only one of many theories. (I know it's not the best source, but Wikipedia has some good information on these)

This may be a bad basis for faith, but on some level it is simply easier to reject all of the competing recent theories and hold fast to tradition. (The Gordian Knot approach.)

When it comes down to it, for me anyway, whether Moses wrote the books or not isn't of the utmost importance. What is important is whether or not I trust that the Scriptures are actually "God-breathed". Since Jesus Himself quoted from the books of Moses, He clearly accepted them as Scriptural. That's good enough for me, so I don't worry about such issues.

Taking the next step, I personally reject the theory simply for the reasons above, but I wouldn't get into an argument over it. I reject the idea, but accept that I could be wrong, and that God could have easily given us exactly the Bible He meant to give us in any way He chose. If I'm wrong about the authorship it doesn't really matter so I don't worry about it, so it's really a non-issue to me but if pressed I'd say I believe the Mosaic authorship.

I suspect that many who reject the theory do so for the same reasons.