Question concerning the Trinity, Jesus’ authority and the Father: “Jesus was only lower than the Father while on the earth, correct? So, He is no longer subject to the Father?”
Jesus and the Holy Spirit are coequal with the Father eternally; there is an agreed upon delineation of authority for the purposes of order, structure, modeling federal headship and this has been relevant from eternity past and most relevant beginning with the creation of the angels.
It is necessitated order and obedience and the violation of same in the Kingdom that initiated the creation of Time, our Universe, our genome; in response, the authority to create matter, Time, physics, was delegated to the Son (John 3:35; Hebrews 11:3); the Gospel i.e. the Plan to deal with a destructive rebellion in the Kingdom, was ordained “before the beginning of Time” (2 Timothy 1:9-10); in fact, the primary reason Messiah took-on flesh via the hypostatic union (Philippians 2:6-8) and entered the Realm of Time was to “destroy the works of the Devil” (1 John 3:8b).
The Father, Son, Spirit have always worked in an agreed upon shared authority first introduced into Time through the identifier of Elohim (Genesis 1:1) a plural noun/singular verb; then, the Holy Spirit introduces Himself in Genesis 1:2; the Triune God works in unison (Us – Our) to form the complex human genome on the Sixth-Day of Creation in Genesis 1:26-28; the Son, Jesus Christ born of the virgin seed to circumvent Adam’s sin-nature, is introduced in Genesis 3:15 and the war between the Son and the Devil is declared within that verse as well; then, the battle strategy that Elohim would use to destroy the works of the Devil (the Gospel) is pictured in Genesis 3:21 with the shedding of innocent blood and the clothing of mankind in God’s “robe of righteousness” while God rejects the works of mankind’s hands (fig leaves) to cover his own sin.
The entire focus of God’s Plan to deal with evil is complete within the first three Chapters of God’s revelation to mankind and His Triune nature is modeled there as well and this was done entirely by God to restore order in His Kingdom while maintaining volitional love with the faithful angelic creation that did not follow the Evil One in the rebellion. It is these faithful angels that Elohim adores and His relationship with them is paramount, forever, while human kind is the byproduct of the Gospel and offered life with God, eternally, only by faith in the Son, Jesus Christ our God who defeated and destroyed death, Hell, the grave, for all who believe.