One of the key components to LDS theology is that of scripture being an open canon.  According to the Church of Jesus Christ of Latter-day Saints’ Bible Dictionary, scripture is defined as follows:

The word scripture means a writing, and is used to denote a writing recognized by the Church as sacred and inspired. It is so applied to the books of the O.T. by the writers of the N.T. (Matt. 22: 29; John 5: 39; 2 Tim. 3: 15). For an account of the process by which the books of the O.T. and N.T. came to be recognized as scripture, see Canon. Latter-day revelation identifies scripture as that which is spoken under the influence of the Holy Ghost (D&C 68: 1-4).
According to this definition, this leaves things pretty wide-open as to what scripture really is and can be difficult for many people, especially those from other faiths to comprehend.  Basically anything that is spoken by someone under the influence of the Spirit can be interpreted as scripture.  However, this also places great responsibility on everyone to be in tune with the Holy Spirit so they can interpret by the spirit and know if things spoken are essentially the word of God. 
As I pondered this, I thought about the scriptures that the LDS currently use commonly called the “Standard Works.”  These scriptures include the Bible, Book of Mormon, Doctrine and Covenants, and Pearl of Great Price.
Most Christians claim that the Bible is infallible and that every single word written therein is exactly what God wants us to have and there can be no more scripture.  This is very hard for LDS people to fathom because they believe otherwise.  Why are such scriptures as the Song of Solomon considered to be considered infallible scripture? Who was it that had the authority to declare that the Bible should be the only scripture?  If the experiences and prophecies in the Bible are the only authorized scripture, what scriptures were the apostles and prophets of the Bible using at the time?
On the other hand, Christians firmly believe that it is heretical to have any additional scripture other than what is in the Bible.  They may have questions and concerns about anyone else who claims to add scripture is a false prophet and therefore their writings and words should be avoided.
Athiests and Agnostics choose to avoid the scriptures altogether because of flaws and condradictions found within the scriptures.
As I contemplate these issues and questions, I’m very grateful for the following scriptures about the Holy Ghost:
Moroni 10:2-5
2 And I seal up these records, after I have spoken a few words by way of exhortation unto you.
  3 Behold, I would exhort you that when ye shall read these things, if it be wisdom in God that ye should read them, that ye would remember how merciful the Lord hath been unto the children of men, from the creation of Adam even down until the time that ye shall receive these things, and ponder it in your hearts.
  4 And when ye shall receive these things, I would exhort you that ye would ask God, the Eternal Father, in the name of Christ, if these things are not true; and if ye shall ask with a sincere heart, with real intent, having faith in Christ, he will manifest the truth of it unto you, by the power of the Holy Ghost.
  5 And by the power of the Holy Ghost ye may know the truth of all things.
John 16: 7;13
7 Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you.
13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.
In the first scripture, there is a promise given that one can know if the things written in the Book of Mormon are true.  However, the promise extends further in verse 5 in that the Holy Ghost will not only help one receive a witness of the Spirit if the Book of Mormon is true, but also know the truth of all things.  Also, in the Bible Jesus says when he leaves the Holy Ghost will show them the truth of all things as well.
If one is to read certain parts of the Bible (such as the Song of Solomon) and if one is to read certain parts of the Doctrine and Covenants (such as the polygamy revelation) it can be hard to feel the Spirit confirm it as truth.  Also, Joseph Smith’s Lectures on Faith used to be “cannonized” scripture but were removed in the early 1900’s.  Furthermore, when Joseph Smith spoke about the Book of Mormon he said that it was the most correct book of scripture written.  But didn’t say it was completely flawless.  I’ve read that the Book of Mormon has been changed and edited over 4,000 times. Also, authors within the Book of Mormon acknowledge their weakness in writing
Acknowleding flaws and/or errors in scripture can be a huge thing for both LDS and Christians to accept.  They both believe that scripture is flawless. Due to the weaknesses of men in writing and translations, etc. and the LDS view of having an open cannon, it is very important–essential–that one maintains a close relationship with the Lord so they can be led by the Holy Ghost to know the truth of all things that are found in the scriptures.
However, this can lead to discrepencies and to people claiming that “the Spirit told them” to say and/or do certain things and believe certain doctrine.  The LDS comeback for this answer would be “that’s why we have prophets and apostles.”  However, the questions then arise: How are we to know if they are indeed prophets and called of God?  How can we know if what they’re speaking is truth?  The answer: the Holy Spirit.
It would take a whole other post to write about how to recognize the Holy Spirit speaking truth to you, but some posts I’ve previously written on this topic include:”Effectively Using the Sword of the Spirit,” “Learning the Mysteries of God,” and “Questions to Know if you’ve Experienced the Holy Ghost.”
I especially like this quote by Gordon B Hinckley:
How do we know the things of the Spirit? How do we know that it is from God? By the fruits of it. If it leads to growth and development, if it leads to faith and testimony, if it leads to a better way of doing things, if it leads to godliness, then it is of God. If it tears us down, if it brings us into darkness, if it confuses us and worries us, if it leads to faithlessness, then it is of the devil” (Jordan Utah South regional conference, 2 Mar. 1997)
I would like to let those who read this know that I’ve felt the Holy Spirit confirm truth to me on numerous occasions throughout my life and that I’m grateful for this.  As I’ve prayed about various scriptures I have felt the Spirit witness truths to me that are found in the Bible, Book of Mormon, and other writings both LDS and otherwise.  I know that I’ve felt the Spirit confirm that there is a God that watches over each one of us and that cares for us.  I’ve felt His love and Spirit as I’ve prayed about big and small decisions in my life and know that he will lead us into the right paths and help us find truth in all things.  I know that God will reveal the truth of all things to everyone if we ask in humility and faith.