What does the Bible say about the old and new commandments?

In 1 John 2:7-11, the Apostle John explains that he writes no new commandment, but rather an old commandment which has been present since the beginning: believing on the Lord Jesus Christ. This old commandment transcends the Law of Moses because it highlights the necessity of faith in the person and work of Christ for salvation. However, John introduces a new commandment, which is not a contradiction to the old but a fuller manifestation of it; it underscores the importance of love among believers. This love is to be modeled after Christ's love for us, which is now central to life under the New Covenant, where Christ Himself becomes our Sabbath and the fulfillment of all righteousness.