The New Testament is so much easier for us to understand than the Old Testament because the original language of the OT was Hebrew. They thought differently than we do. However, the writers of the NT knew the OT very well and when God breathed these words to men; it was to men who understood it very well. When we understand OT, it is like understanding the foundation of our faith. Like going to grammar school as preparation to High School.
Hebrew thinking was very concrete, they thought of the physical basis of spiritual truth. To them, love had to do with family that God chose for them. When God blessed it meant giving us gifts. Atonement meant a covering. They studied scripture to learn the patterns of how God worked, what his God principles were. We think in an aesthetic way. We think of the spiritual without relating it to the physical. That makes it hard for us to understand the OT. I found one man who gives OT lessons without adding his personal agenda, as so many teachers do. It is a website called Torah Class.
The entire goal of scripture is for us to learn to live eternally with our God. Christ fulfilled this goal of the OT; he was the blood sacrifice we use for repentance so we may be holy enough to live with our God. The background of this is in the OT, but the gospel of John puts it together better than any other book.