Jesus has two natures, one human and the other divine. Here he is speaking through his human nature.
Blessed be the holy Trinity and undivided Unity;
we will give glory to him, because he has shown his mercy to us.
Trinity Sunday is celebrated in all the Western liturgical churches: Roman Catholicism , Anglicanism, Lutheranism, Presbyterianism, and others.
Why Does Jesus Say That the Father Is Greater Than He If the Members of the Trinity Are Equal?
A common question arising around the time of Trinity Sunday is rooted in this passage from John’s Gospel:
If you loved me, you would be glad that I am going to the Father, for the Father is greater than I (Jn 14:28).
This is somewhat puzzling because we are taught that each Divine Person of the Blessed Trinity fully possesses the nature of God and is equally to be adored and glorified. What, then, did Jesus mean when He said, “the Father is greater than I”?
The most common (and correct) answer is that in this passage Jesus was speaking in reference to His human nature, in which He is inferior to the Father; in His divine nature He is equal to the Father. Many of the Church Fathers spoke in this way. For example,
St Augustine said, Let us acknowledge then the twofold substance of Christ, the divine, which is equal to the Father, and the human, which is inferior. But Christ is both together, not two, but one Christ: else the Godhead is a quaternity, not a Trinity. Wherefore He says, If ye loved Me, ye would rejoice, because I said, I go to the Father; for human nature should exult at being thus taken up by the Only Begotten Word, and made immortal in heaven; at earth being raised to heaven, and dust sitting incorruptible at the right hand of the Father. Who, that loves Christ, will not rejoice at this, seeing, as he doth, his own nature immortal in Christ, and hoping that He Himself will be so by Christ (Quoted in the Catena Aurea at John 14:28).
Didymus the Blind said, When he says “greater” he indicates that his divinity can be equaled to the Father, since he is of the same substance as him, but the Father is greater because the Son accepted a body…The Son’s nature is understood to be less than that of the Father inasmuch as the Son became man (Fragments on John at 14).
Hilary of Poitiers said, By the birth of the Son the Father is constituted greater … in that the Son, born of the Father, after assuming an earthly body, is taken back to the glory of the Father (On the Trinity, 9:56).
Theodoret of Cyr had Jesus speak, saying, Sometimes therefore I, [Jesus] say that I am equal to the Father, and at other times say that the Father is greater than I. I am not contradicting myself, but I am showing that I am God and a human being … If you want to know how the Father is greater than I, I was talking from the flesh, not from the person of the Divinity (Dialogue 1:56).
Thus, the first answer is clear: As God, Jesus is equal to the Father, but as Man, He is inferior to the Father.
In a qualified way, however, it is also possible to speak of a particular greatness of the Father even within the Trinity. While all three persons of the Trinity are co-eternal, co-equal, and equally divine, the Father is the Principium Deitatis (the Source in the Deity). So, although the members of the Trinity are all equal in dignity, there are processions in the Trinity. The Father is the Principium, the Son eternally proceeds from Him and is eternally begotten by Him (Jn 8:42); the Holy Spirit eternally proceeds from the Father and the Son as from one principal (Jn 15:26).
Thus, even from the perspective of His divinity it is possible for Jesus to say, “I delight that the Father is the eternal principal of my being. Even though I have no origin in time, I do eternally proceed from Him.”
St. Thomas Aquinas speaks poetically of the Trinity in the familiar hymn “Tantum Ergo”:
Genitori, Genitoque … Procedenti ab utroque … compar sit laudautio.
(To the One Who Begets, and to the Begotten One, and to the One who proceeds from them both, be equal praise.)
So, although the Persons of the Trinity are equal, the processions within the Trinity do have an order. The Father is “greater” in the very qualified sense that He is the Principium Deitatis, the Principal of the Deity, but is co-eternal and equal in dignity to the Son and the Holy Spirit.
Devotionally, Jesus may also be speaking of the Father as greater in the sense that He always does what pleases His Father. Jesus loves His Father; He’s crazy about Him. He is always talking about Him and pointing to Him. By calling the Father “greater,” Jesus says (in effect), “I look to my Father for everything. I do what I see Him doing (Jn 5:19) and what I know pleases Him (Jn 5:30). As God, we share one will; as human, my human will and His will are one. What I will to do proceeds from Him. I do what I know accords with His will.”