Many times when someone discusses what the Bible teaches they may use, even unbeknownest to them, what is called Proof Text. Proof texting uses certain short passages, many times only a single verse, pulled from the Bible in support of a particular belief or doctrine.
The problem with this method is that the person who is Prooftexting usually gives their selected verses a meaning that may be entirely different from what the writer intended. The Bible is written in such a way that most verses cannot be correctly understood in a stand alone fashion. The context of a particular verse, who wrote it, when did they write it, where did they write it, etc. is needed to arrive at its intended inspired meaning.
Proof texting can easily lead to wrong conclusions regarding what is the truth of God. An argument or doctrinal stand that relies heavily on proof text is ultimately considered weak. In fact, those who preach and teach others based on such texts are generally viewed negatively by true Biblical scholars and those who seriously study the Bible.
A better way of understanding the scriptures is through what is called Hermeneutics. This technical term simply refers to the process or method of carefully analyzing the meaning of a particular passage. Factors such as who wrote the text, the time period it was written, where and to whom was the passage written, etc. need to be considered in order to arrive at a correct understanding of what the Biblical text teaches. Additionally, any interpretation needs to consider what other parts of the Bible say that are related to what is being studied.
10 For it is precept upon precept, precept upon precept, line upon line . . . (Isaiah 28:10)