Thanks for asking a question on www.thisisyourbible.com
It is absolutely important to have a basic understanding of the entire Bible - both Old and New Testaments. Here is a startling demonstration of this fact:
Matthew 1:1 The book of the generation of Jesus Christ, the son of David, the son of Abraham.
Who are David and Abraham and why are they so important that they are mentioned in the very first verse of the New Testament and in the same breath as the Lord Jesus Christ himself?
The point is that you can't understand even the very first verse of the New Testament without at least a good overview understanding of the Old Testament.
I hope you have found this helpful.