Here is another quote about this from Dr. Andy Woods.
“[L]et us consider the book of Revelation.
“There are 404 verses in the book of Revelation. Interestingly, there are no Old Testament quotes in the book of Revelation, but there are many Old Testament allusions in the book of Revelation. And 278 of Revelation’s 404 verses are allusions back to the Old Testament. That is how you demystify the book of Revelation.
“People say, ‘I cannot understand the book of Revelation.’ Well, if most of it is a recapitulation of the Old Testament, what you are conceding and admitting is that you do not really know much about the Old Testament!
“The bottom line is that you simply cannot teach the whole Bible without teaching the Old Testament. It would be like trying to learn how to do multiplication and division without first learning addition and subtraction. You cannot do it. You cannot write a paragraph unless you know how to write a sentence, you cannot write a sentence unless you know how to spell words and you cannot write a word unless you learn the alphabet. If we are expecting people to just pick up all of the truths found in the Old Testament—at the New Testament level—we are asking them to do something that is impossible.”
“Be diligent to present yourself approved to God as a workman who does not need to be ashamed, accurately handling the word of truth.” 2 Timothy 2:15
Because He first loved us and we want to accurately handle His Word of truth,