Missing the Point
As times change, so do thoughts, ideas, and especially issues. Some of what were issues to Paul in his day are not issues for us in our day, and vice-versa the things that are such big deals and cause great division and perplexity were sometimes matters of general agreement in his day. This change in primary issue colors our reading when we study Paul's writings today. We often "read into" what he was saying points that are for or against our view on the issue of the day.
In Galatians, for example, Paul was battling the idea that the Old Testament sanctuary services were somehow still essential to salvation. Today there is hardly a Christian who would argue that we must offer sacrifices, worship at the temple, or keep ceremonies that specifically foreshadowed the coming of Christ.
Instead, today, we argue about whether or not God means us to keep His 10-Commandments.
If we apply Paul's arguments (against the sanctuary services) to our modern discussion of God's 10-Commandments, we will misunderstand and misapply what Paul was saying, and miss the blessed truths he intended the world to understand.
Simon Peter's Warning
As we study the writings of Paul, the Apostle Simon Peter has words of counsel for us: "Wherefore, beloved, seeing that ye look for such things, be diligent that ye may be found of him in peace, without spot, and blameless." Now today, many of us, instead of being found "without spot and blameless", wrest Paul's words as an excuse to break God's law, and let a great many "spots" and "blames" hide under a variety of ideas we think Paul was teaching. But Peter continues: "Our beloved brother Paul also according to the wisdom given unto him hath written unto you; As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction." 2 Peter 3:14-16
We must be learned. How do we do this? Isaiah 28:9-10 has the answer: "Whom shall he teach knowledge? and whom shall he make to understand doctrine? them that are weaned from the milk, and drawn from the breasts. For precept must be upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little." Only by comparing one Bible writer with another—by taking all of God's Word as our guide comparing scripture with scripture, precept with precept, line with line—a little here and a little there: this is the way we become learned and will be able to understand doctrine.
While we do this, we must pray for the enlightenment of the Holy Spirit and it will be given!
Missing the Argument
Much of Paul's writings have been separated from their context by the fact that we know them so well. Many beautiful thoughts that were key points in a connected argument have been extracted to stand on their own.
"By grace are ye saved through faith." "I am crucified with Christ…" "All have sinned" "The wages of sin is death." "By beholding we become changed."
These thoughts have been disconnected from their original line of thought and made to stand on their own (which incidentally they do quite well)!
However, because of this, we tend to think of Paul's writings as a disconnected collection of beautiful thoughts rather than a well thought out argument for toward a particular point.
To understand his writings one must take in at once multiple chapters, or even entire books. By committing these passages to memory, or at the very least reading them in their full context multiple times, and then as above comparing scripture with scripture, we may learn what Paul was actually teaching.
Again, while we do this, we must pray for the enlightenment of the Holy Spirit—and if we ask, it will be given!