Many people have a vague belief in God but refuse to accept Jesus as anything more than a great human teacher. But the Bible does not allow that option. Both the Old and New Testaments proclaim the deity of the one who came to save and to reign. Jesus explained that this psalm spoke of the Messiah as greater than David, Israel's greatest king (Mar 12:35-37). Peter used this psalm to show that Jesus, the Messiah, sits at God's right hand and is Lord over all (Act 2:32-35). You can't straddle the fence, calling Jesus "just a good teacher," because the Bible clearly calls him Lord.
Psalms 110:1
This is one of the most-quoted psalms in the New Testament because of its clear references to the Messiah. In Mat 22:41-45, Jesus recited the words of this verse and applied them to himself. Verses 1 and 6 look forward to Christ's final and total destruction of the wicked (Revelation 6-9); Psa_110:2 prophesies Christ's reign on the earth (Rev_20:1-7); Psa_110:3-4 tell of Christ's priestly work for his people (Hebrews 5-8); and Psa 110:5-6 look forward to the final battle on earth when Christ will overcome the forces of evil (Rev 19:11-21).
Psalms 110:4
As a priest like Melchizedek, Christ will never abuse his divine position, and his reign will be forever. Jesus is more fully described as our High Priest in Hebrews 5.