Thinking in terms of God’s so-called perfections can actually be a tricky complex. Is there a way to prioritize them; do we think them speculatively (in se), or concretely (ad extra)? Even through the cursory questions I just noted what we quickly come to realize is that what is at stake, in regard to answering how we approach the perfections, vis-à-vis knowledge of God, implicates our prolegomena; or theological methodology. For this Evangelical Calvinist, as many of you know, following both Thomas Torrance and Karl Barth (not to mention Athanasius et al), I prefer to think God from His economic revelation, which I take to be synonymous with His ontological/immanent/antecedent reality as the triune God. As Jesus said to Phillip,
8 Philip said, “Lord, show us the Father, and we will be content.” 9 Jesus replied, “Have I been with you for so long, and you have not known me, Philip? The person who has seen me has seen the Father! How can you say, ‘Show us the Father’? 10 Do you not believe that I am in the Father, and the Father is in me? The words that I say to you, I do not speak on my own initiative, but the Father residing in me performs his miraculous deeds. 11 Believe me that I am in the Father, and the Father is in me, but if you do not believe me, believe because of the miraculous deeds themselves. –John 14:8-11
When we see Jesus [Καὶ ὁ λόγος σὰρξ ἐγένετο καὶ ἐσκήνωσεν ἐν ἡμῖν] we see the triune God’s work and person, without remainder, in the Son’s enfleshment. In other words, when the Son incarnate shows up, He comes as Son of the Father, as Athanasius famously emphasized; and He does so by the creative creativity of the Holy Spirit’s activity as the One who works as the bonding agent between the Father and the Son in the effulgence of their three-in-one / one-in-three love. It should be apparent by now what ‘perfection’ I take to be the ground of all others. In other words, it should be clear that I take who God is as Self-revealed love to be the ground and shape of all the other so-called perfections the Christian tradition likes to think God through. Ian McFarland affirms this way of thinking about the primordial perfection of God as triune love. And he thinks that the way we think God ought to come from the primacy of God’s Self-revelation as revealed in the οἰκονομία of His life for the world come in the flesh and bone of Jesus Christ. He writes the following in summary of previous development he has given in the broader context from which this is taken:
In summary, to say that God is love is to confess God as Trinity: the Father, the Son, and the Holy Spirit. God is love in that the Father loves the Son in giving all that he is to the Son and confirming this in the Spirit, even as the Son loves the Father by glorifying the Father in the same Spirit, with the Spirit bearing witness to—and thereby sharing in—the mutual love of the Father and the Son. In other words, “love” characterizes God’s concrete existence as these three, traditionally designated as hypostases or “persons.” As realized in the communion of the three persons, the love of God is free, in that it is not involuntary or compelled as though grounded in a reality either logically or ontologically prior to the act of the divine persons’ loving one another. Rather, God loves freely, and thus willingly, since it is integral even to the human love of which God’s is both the ground and goal that love can never be unintended, as though a lover could refrain from acknowledging her love as he own act. At the same time, the freedom of divine love does not make it a matter of choice or decision, as though God’s freedom were to be understood as its cause. If love were in this way the product of some more fundamental divine activity (viz., the divine will), then it would not be strictly true that God simply is love. For us, love is adventitious, in that we are before we love. It is not so for God, since the mutual love of the Father and the Son in the Holy Spirit is just what it means for God to God: neither relative to or dependent on any nondivine reality, but simply the One who lives in and as three persons.
There are some technical things McFarland is addressing (at least as I read in-between the lines), in the literature, but we won’t let that detain us here. What is instructive for our purposes is to simply press the point that who God is is love; as the epistolero puts it in the starkest of terms: ‘The person who does not love does not know God, because God is love.’ Per the Scriptural attestation, and the reality it attests to in Jesus Christ, this is indeed the primary perfection by which all other so-called perfections take shape. If this is so, it tells us that at the very heart of what God does, because He never does anything apart from who He is, is that it is shaped by His overflowing life of Triune love.
When we have theologies that take their relative shape from metaphysical and speculative categories—such as we have in Christian Aristotelianism—God is not thought, primarily from His perfection of love, but instead from discursive reasoning that posits God as the necessary Creator; attendant, of course, with all the other speculative perfections such as eternality, impassibility, immutability, the omnis, so on and so forth. When God is thought under these pressures, alien pressures relative to His Self-revelation, in regard to Who God is, it changes how the Christian thinks a God-world relation. In this frame, no longer does God’s relationship to, for, and with us come attenuated by God is [first] love; instead it comes with the emphases that God is sovereign Creator, who now relates to the world, to us through (in the Reformed case) impersonal decrees that come with a juridical frame.
It is best to think God from the centraldogma that He is love. We can think through the other ‘classical’ categories, but not unless we do so first through the lens of God’s Triune love as the ‘ground and grammar’ of all the other attributes that are present within the Divine life; within the mysterium Trinitatis. Love you, Jesus. Love you, Father. I say so by the Holy Spirit who has brought me into Your life through the anointed and vicarious humanity of Jesus Christ.
 Ian A. McFarland, The Word Made Flesh: A Theology of the Incarnation (Louisville, Kentucky: Westminster John Knox Press, 2019), 29-30 kindle.
 I John 4:8, NET.