What Is the Connection?
God Cannot Be Infinite Without Also Being A Se
If God is truly infinite and limited by nothing in essence, then surely he does not need to be all that he is in and of himself, one might say. For if he can do anything he pleases then he does not need himself to survive and live, for he can find life in something else if he so freely chooses. God the Son came to the earth and lived as a human being, thus finding life in a human form. Therefore, God does not even need himself for existence or life for survival.
On the contrary, God most necessarily is exactly who he is, infinite in every way, because he is life himself, (Jn. 14:6). If he was not a se then he could not be infinite. He is the source of life, light, and he is all-love. He gives life to all his creation (Acts 17:25), because “God has life in the truest sense.”  Since God possesses life in the highest degree, he has “the most perfect and everlasting life because his intellect is most perfect and always actual.”  God must be all that he is in and of himself for him to be limitless because, as found in Scripture, he is the very definition of life and no life can be found outside of him. For God to not be a se means God could not exist, much less be infinite in any way.
Moreover, God, being all that he is in and of himself, brings definition to all in creation because of who he is. Since all came from God, created by and through the Word (Col. 1:16), he is the source of life, and not only life, but also purpose, existence, light, joy, and characteristics for all his creation. For God to seek life in anything other than himself, he would have to cease to sustain his creation. If God were to cease to providentially sustain any of his creation, all things would cease to exist, including God. Therefore, for anything to exist, everything must exist through one self-existing thing. This thing is the One, true, supreme being which exists through itself: in and of himself. 
God Cannot Be A Se Without Also Being Infinite
If God is completely self-existent in and of himself, relying on nothing for power or life, then it is possible that God can simply choose to be limited by something for a time out of love or affection if he so chooses. For example, in the Bible we see that Christ came down and entered time as a man. Out of love, God the Son freely chose to limit himself by time, space, and matter to be born of a virgin, live righteously, die on the cross, rise on the third day, and ascend on high for the salvation of his people (Phil. 2:6-8).
On the contrary, during the incarnation of Jesus, God does not subtract anything from his nature or essence.  For God to be limited by time would subtract eternity from the nature of God. Rather, he adds a human nature to the divine nature thus being Jesus the Son of God; one person, two natures,  though not adding anything to his divine nature. In fact, God cannot change, add, or subtract anything by nature. If he were to change in the slightest, he could then not be God, for “God is not man, that he should lie, or a son of man, that he should change his mind.” 
Moreover, if God according to His divine nature were to suffer and be passible in time, as the Son, according to His human nature, suffered on the cross, then God, in his essence, would be susceptible to change in emotions and feelings, and thus, he would be able to change in other respects as well. However, “God is unchangeable in his essence, nature, and perfections.”  God the Son, in his divine nature never limited himself to time, space, or matter in the incarnation, but merely took on a human nature that was limited by time, space, and matter, yet still being fully God and fully man.
When the incarnate Christ did come and suffer, his divine nature did not suffer in that it was susceptible to emotional change, but he suffered in his human nature, as a man. Christ did not cease to be divine for the duration of the crucifixion, but “the person of the Son tasted death the only way he could – humanly…”  Christ merely “does according to his human nature and what he does according to his divine nature.”  Scripture clearly teaches us that in the work of Christ, he acts according to both natures, and “by each nature doing that which is proper to itself.” 
Therefore, to say that God freely chose to limit his nature for the love of mankind, is simply to diminish the absolute sovereignty of the God of the universe, and to declare that this God depends on his creation to satisfy his longings. God must be infinite, being bound by nothing outside of himself, and be absolutely perfect in and of himself. Since God comes from nothing, and is self-sufficient with life in and of himself, he must be infinite and perfection itself.  Since God truly is a se and infinite, to worship any other god besides the God of the Bible is idolatry. 
Since God Is A Se and Infinite, He Is, Therefore, God
God is full life in and of himself, absolute and perfect in essence and nature; being limited by nothing in nature and being, he is God. The Triune God of the Bible is complete in all that he is and infinite in every respect. For nothing is like God and God is not like anything we can comprehend.  This God of the universe made himself known to the Israelites when he said, “The LORD, the LORD, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, keeping steadfast love for thousands…,” (Exodus 34:6-7). John Calvin expounds on that passage saying,
“that his eternity and self-existence are declared by his magnificent name twice repeated; and, secondly, that in the enumeration of his perfections, he is described not as he is in himself, but in relation to us, in order that our acknowledgment of him may be more a vivid actual impression than empty visionary speculation.” 
Not only does God seek to teach us who he is, but we are to know and understand who we are considering all that he is, because all of his blessings bestowed upon us are because of who he is in and of himself. All blessings flow from God’s aseity and infinite goodness. Amen amen.
In Part III of this series I will briefly show how God’s aseity and infinitude relate and connect closely with his simplicity, immutability, eternality, and goodness.
 Thomas Aquinas, “Summa Theologiae,” in Cambridge Texts in the History of Philosophy, ed. Brian Davies and Brian Leftow (Cambridge: Cambridge University Press, 2006), Ia.18.3.
 Anslem, “Monologion,“ in The Major Works, ed. Brian Davies and G. R. Evans (Oxford: Oxford University Press, 1998), 3.
 1689 LBCF, 2.3.
 John Calvin, Commentaries on the Epistles of Paul the Apostle to the Philippians, Colossians, and Thessalonians, trans. and ed. Rev. John Pringle (Grand Rapids, MI: Baker Book House, 1999), 57.
 Numbers 23:19. Also see Psalm 15:4 and Malachi 3:6.
 Stephen Charnock, The Works of Stephen Charnock Vol. I (Edinburgh: Banner of Truth, 2010), 380.
 Rob Lister, God is Impassible and Impassioned: Toward a Theology of Divine Emotion (Wheaton, IL: Crossway, 2012), 278. Emphasis original.
 Ronald S. Baines, Richard C. Barcellos, James P. Butler, Stefan T. Lindblad, and James M. Renihan, eds., Confessing the Impassible God: The Biblical, Classical, & Confessional Doctrine of Divine Impassibility (Palmdale, CA: RBAP, 2015), 223.
 1689 LBCF, 8.7a.
 Aquinas, Summa Theologiae, Ia.7.1.
 Exodus 20:1-11; Deuteronomy 11:1.
 Exodus 8:10; 1 Samuel 2:2; 2 Samuel 7:22; 1 Chronicles 17:20; 2 Chronicles 14:11; Psalm 77:13; 113:5.
 John Calvin, Institutes of the Christian Religion, trans. Henry Beveridge (Peabody: Hendrickson Publishers, 2008), 10.2.