Jesus preaches the Holy Spirit
Christ, our Redeemer and Salvation, Hiimself testifies and preaches to us in the finest manner that the Holy Spirit is the eternal and omnipotent God. Otherwise he would not put His command of holy Baptism as He does when He says: "Go ye, therefore, and teach all nations, baptizing them in the name of the Father and of the Son and of the Holy Ghost, teaching them to observe all things whatsoever I have commanded you" (Matthew 28:19-20).
Since He puts the command this way in express words, it must follow that the Holy Ghost is true, eternal God, coequal from eternity with the Father and the Son in power and might. Otherwise Christ would not place Him on a level with Himself and His Father in a work on which forgiveness of sin and eternal life depend. (What Luther Says - #2044)