Differences in the Bible
(2 Timothy 2:15 KJV) Study to show thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.
Two groups of people through whom God will accomplish His purpose:
There are different divisions, distinctions, and differences in scripture pertaining to each group, which cannot be mixed.
In time past, one was under the law and had to work/perform to maintain their righteous standing before God. (Luke 1:6)
But now, today in the dispensation of grace, one is under grace and it is not necessary to perform in order to maintain one's righteous standing with God. Today the basis for our righteous standing before God is not based on what we do but on what Christ has accomplished on the cross. (Romans 4:4-5, 11:6)
Ages to come, God resumes what He was doing in time past.
There are messages in scripture written to two different groups of people, God's earthly kingdom people (Israel) and God's heavenly kingdom people (the body of Christ). God has temporarily set aside the nation of Israel (Romans 11:11-12, 25-26) to accomplish His purpose with the present day church. This is why we have to ask these questions whenever we study God's Word:
While the whole Bible is for our learning and admonition it is not all to us and about us.
Recognizing the two distinctive groups of people God will use to accomplish His purpose is the dispensational way of Bible Study.