The I here is David, a type of Christ, indicating that this word is the word spoken by Christ to God. In this psalm David, God’s anointed, typifies Christ as the man anointed by God to reign over the earth for God.
Lovingkindness and justice will be the base of the reign and judgment of Christ, typified here by David. Therefore, this psalm unveils how Christ will reign over the earth with lovingkindness and justice and deal with all the wicked (vv. 1, 6, 8).
This is how denominations are formed. The main direction is to come out of the system; it cannot change. "I began to realize that our practices have differed and deviated from our vision. Our vision was the same, our teaching was mostly the same, the truth is always the same, but our practice has really differed."