There is no Old Testament or Old Covenant. Jesus does talk of the New Covenant.
Modern church tradition is full of commonly accepted assumptions about the Bible, and many of them are not true.
The term (or words) Old Testament and New Testament do not appear in the original text.
Just like the page numbers, they were added by humans to make reading ad understanding easier. Sometimes this cataloging is useful and speeds up reading and assist understanding but often they actually confuse or or create assumptions that are harmful to our understanding.
There are not two testaments in the Bible. We have a number of covenants recorded in the Bible. The two that we are most familiar with are the Mosaic Covenant (often called the law) and the New Covenant.
Other are, The Noahic Covenant, The Abrahamic Covenant, and The Davidic Covenant.
Many Christians disregard huge portions of scripture buy saying "that's the old Testament" when in fact there is no "Old Testament". for example prophecies of judgement in the Major Prophets cannot be thrown out with the glib, and uneducated, its the Old Testament.
Many of the prophecies in the Prophets, have not yet been fulfilled. These promises will thus be fulfilled during the time that baby Christians lump under, "The New Testament".
The main point here is, we need to become dramatically more astute in our handling of scripture, if we have any intention or really knowing God.
15 Be diligent to present yourself approved to God, a worker who does not need to be ashamed, rightly dividing the word of truth.
2 Timothy 2:15
After-all we must love God with our minds too.