We end our prayers with the word Amen. That word means "so be it." It's a covenant term from the Old Testament. When Israel entered into the old covenant, known as the law of Moses, they spoke collectively the word Amen to agree with the commandments. Today, we use the same term to end our prayers.
The old covenant law was conditional, based upon the obedience of the people. The new covenant is unconditional, based upon the complete and perfect obedience of Jesus Christ. Therefore, we pray "in the name of Jesus. Amen." That means believers in Jesus Christ our Lord receive all of God's covenant promises.
The Bible teaches that Jesus is our Amen, according to the new covenant, also known as the everlasting covenant (Hebrews 13:20-21). Observe the contrast. Under the old covenant, the people promised with an Amen to obey God. Yet, they disobeyed. However, under the new covenant Jesus is our Amen. Jesus is the "Amen, the faithful and true witness, the ruler of God's creation" (Revelation 3:14).
According to the law, we are all covenant breakers. In essence, we have all sinned (Romans 3:23). Jesus came to fulfill the law and bring the promises of the new covenant. Jesus is our Amen of all the promises of God (2 Corinthians 1:20). All of the promises of God are for us through the perfect obedience of our Lord Jesus Christ!