From “Introduction to Philosophy: A Christian Perspective” (Geisler, Feinberg):
”(1) Good and evil are either judged by a standard beyond themselves or they are judged by each other.
“(2) But if they are judged by a standard beyond themselves, then that is the one and only ultimate by which all is judged (which is actually the theistic definition of “God”).
“(3) If good is judged by evil, then evil is the single ultimate by which all else is measured.
“(4) If evil is judged by good, then good is the single ultimate by which all else is measured.
“(5) In both cases there is one, not two, ultimate standard (contrary to dualism).
“Further, as Augustine pointed out in reply to the Manichaeans, evil is measured by good and not the reverse. For when we take all that we call evil away from something, then what is left is better (for example, remove all rust from a car and one has a better car). But when we take all that is good from something, then nothing is left. Good, therefore, is the positive and evil is the privation, or lack of good,” (330-331).
Rewrite the above argument this way:
(1) If good is judged by evil, then evil is the single ultimate by which all else is measured.
(2) If evil is judged by good, then good is the single ultimate by which all else is measured.
(3) In both cases there is one ultimate standard (contrary to dualism).
That seems to make a non-personal "good" be the ultimate standard. Good is love, agape love must be chosen, choice is made by a person -- the ultimate good/love/choosing is God. Option 2 is the reality, with 'good' being God.
This quote is taken from pages 329-330 of “Introduction to Philosophy: A Christian Perspective” (Geisler, Feinberg) --
b. the second argument for dualism
The second argument for dualism is more of an argument against non-dualism (especially theism). The dualist says that the theist cannot escape the following conclusion:
(1) God is the author of everything that exists.
(2) Evil is something that exists.
(3) Therefore, God is the author of evil.
Since theists affirm God’s sovereignty and creative power over all that exists, they cannot deny premise 1. Likewise, since theists do not, like pantheists, deny the reality of evil, they cannot deny premise 2. But this means theists seem stuck with an unwanted conclusion, since it makes God directly responsible for creating evil.
Theists respond to both premises. First, God is the author of some things only indirectly. For example, God created freedom, but He does not perform acts of evil Himself or through man’s free choice. To state it another way, God does not create evil directly or essentially but only incidentally. God is directly responsible only for the fact of freedom, not for all the acts of freedom. Of course, God did create the possibility of evil when He made men free. But it is free creatures who bring about the actuality of evil. God is indirectly responsible for evil in that He made evil possible. But the possibility of evil is actually a good—it is necessary for human freedom. The power of free choice is a good power; the fact that men abuse freedom does not make freedom bad. Men abuse everything, including the water and air in their environment. But this obviously does not mean that water and air are bad.
Many theists also object to the second premise. Evil is not a “thing” (or substance). Evil is a privation, or absence of good. Evil exists in another entity (as rust exists in a car or rot exists in a tree), but does not exist in itself. Nothing can be totally evil (in a metaphysical sense). One cannot have a totally rusted car or a totally moth-eaten garment. For if it were completely destroyed, then it would not exist at all. The Christian points to Scripture which says everything God made was “good” (Gen. 1:31); even today “every creature of God is good” (1 Tim. 4:11), and “nothing is unclean in itself” (Rom. 14:14). To be sure, the Bible teaches that men are totally depraved in a moral sense, since sin has extended to the whole man, including his mind and will (Rom. 3; Eph. 2). But total depravity is to be taken in an extensive sense (affecting the whole man), not in an intensive sense (destroying the very essence of man).
When the theist says that evil is no “thing” (substance) he is not saying evil is “nothing” (that is, unreal). Evil is a real privation. Blindness is real—it is the real privation of sight. Likewise it is real to be maimed—it is a genuine lack of limb or sense organ.
Evil is not mere absence, however. Arms and eyes are absent in stones, but we would not say that stones are deprived of arms and eyes. A privation is more than an absence; it is an absence of some form or perfection that should be there (by its very nature).
The form or perfection that should be there (by its very nature) is what God started with. Evil came later. So, good is the default, the eternal. So God did not create the devil/demons or the fallen world – He created perfect angels and perfect humans, and the means by which He would reconcile our relationship with Him. That God is beyond time does not mean what we all are going through is a delusion. Our experience of past, present, future -- of time -- is what it is. Our free will or nature apart from God's will or nature (as opposed to freely willing in line with God's will) is the origin of evil (in time). God cannot will against His own good nature. Whence comes the temporal if not from the eternal? So then, does that make the eternal... temporal? -- does it make the temporal... eternal? No; but God (eternal) transcends, and is within, the temporal -- and the two are distinct. The eternal has control over the temporal, but the temporal never has control over the eternal, unless the eternal allows it (for example, a granted prayer request). From an eternal perspective, evil is temporal and will not last forever. Only God and His goodness, and all that He sustains in existence, will last forever.
In a sentence: evil is “good messed up”. Without good, you cannot have evil. But – you can have good that is not messed up. You don’t have to have something “messed up” right next to something “not messed up” in order to appreciate the goodness of something that is “not messed up”.
Adam and Eve (or humans before sin) knew good by default, like spiders know webs and birds know nests. It was the nature of our relationship with God. Evil was unknown until unity with God was broken. It was known/felt because it was a change in what they knew of good.
The reason God told Adam and Eve, “Don’t eat the fruit of the tree of the knowledge of good and evil” – is because we’re better off not knowing the difference. We’re better off innocent. We’re better off thinkin’ “It’s all good.” But it would not have been love if He had actually prevented us from making that choice. Imagine being God in that moment, when Eve is contemplating tasting the fruit, bringing it up to her mouth, God knowing all that results from that one little taste (everything behind us, and everything before us).
Once they broke unity with God, they were no longer innocent like children... they became self-conscious, shameful. The fact that they became ashamed "after" eating the fruit is proof that they knew good without knowing evil before the fall. It is a good thing to have discernment in this present world (one cannot avoid evil if one can not discern between good and evil), but you can probably understand how every human goes through this Garden of Eden experience when they lose the innocence of childhood and break away from their parents (who feel pain at this, but who allow it out of love, even give opportunities for it, as did God) to find their own way in the world (the parents thinking "one day they will know exactly what I was talking about, though right now my warnings seem arbitrary"). Observe the fact that innocence ("It's all good") is the default (although, for infants after Adam and Eve, they don’t start out in perfect union with God)... a blissful ignorance of evil... a knowing of only good, though one doesn't "know" one "knows" it (like birds don't "know" they "know nests" and spiders don't "know" they "know webs"). It hurts to let our little ones grow up... it hurts so much... and it hurt God, too. Love ain't all fun and games... but it's worth it.
On evil that is better labeled ‘suffering’ (because it does not involve a moral choice) --
“Trouble and suffering are not merely punishment for sin; for God’s people they may serve as a trial (as here) or as a discipline that culminates in spiritual gain (see 5:17; Deut 8:5; 2 Sam 7:14; Ps. 94:12; Prov 3:11-12; 1 Cor 11:32; Heb 12:5-11),” Zondervan’s NASB Study Bible note on Job 2:10.