Many would like to avoid the Old Testament like it was the plague. The truth is we cannot. The Old Testament is the Word of God along with the New Testament. Granted, Jesus fulfilled the old covenant along with the Jewish sacrificial systems, but does that mean the promise made in the Old Testament apply for Christian living under the New Covenant?
Listen and follow along with John Piper as he looks at Isaiah 41:10, Galatians 3, and 2 Corinthians 1:20 to answer that question: