"Some things hard to understand"
As we all know, some passages of Scripture are harder to understand than others. Christians may even
disagree on the interpretation of some parts of Scripture. But, of course, the gospel is so clearly put forth
that even a child can understand it.
2 Peter 3:15-16 is a very telling passage. The first part says this:
And think of the long-suffering of our Lord [as] salvation, as also our beloved brother Paul wrote to you, according to the wisdom given to him; as also in all his epistles, speaking in them concerning these things, in which are some things hard to understand ...
Peter, by the inspiration of the Holy Spirit, says that some of the things Paul wrote are hard to understand! Some people could use this to excuse those who misinterpret some Scriptures to the point of questioning certain gospel doctrines or even putting forth things that oppose gospel doctrines. Yet look at what Peter says next:
... which the unlearned and unsettled pervert, as also [they do] the rest of the Scriptures, to [their] own destruction.
Now that's quite a statement! Here it is all together:
And think of the long-suffering of our Lord [as] salvation, as also our beloved brother Paul wrote to you, according to the wisdom given to him; as also in all his epistles, speaking in them concerning these things, in which are some things hard to understand, which the unlearned and unsettled pervert, as also [they do] the rest of the Scriptures, to [their] own destruction.
Instead of excusing these people who misinterpreted the passages because they are hard to understand, he says that they pervert these hard-to-understand Scriptures to their own destruction! What does this mean? It means that when someone comes to a hard-to-understand passage and interprets it in such a way as to undermine/question/oppose essential gospel doctrine, he shows he is unregenerate! The difficulty of the passages is no excuse! Note that the people who pervert the hard-to-understand passages are called "unlearned and unsettled" -- being unlearned and unsettled is also no excuse!
Does that mean that everyone who misinterprets any unclear passage of Scripture is unregenerate? No, that's not what it's saying. As long as the person remains orthodox in essential gospel doctrine, that person can have a different interpretation than another person who remains orthodox in essential gospel doctrine. But a regenerate person will not interpret a hard-to-understand passage in a way that undermines/questions/opposes essential gospel doctrine.
So when we approach a hard-to-understand passage of Scripture, we know that it does not undermine/question/oppose essential gospel doctrine, and we will never interpret it in such a way.