If God, being perfect, creates something then in some way that thing does not have His attributes. For a start the created things existence depends on the other. Logically they must be different. If being perfect includes being able to create then the created thing is less than perfect. The created thing cannot become a first cause because it was created. If the created thing is less perfect than the Creator then the created thing is imperfect. If the created thing is imperfect it is evil [i.e.not able to obey God of itself, for this it would always need God's enabling at some level]. Is it not inevitable that anything that a holy God creates must be less than holy than Himself i.e. evil? How could a perfect God create evil? How could He do create anything else?
All Monotheistic theologies/philosophies struggle with this question. Monists have no problems with the question. The Advaita (monistic) philosophy says the question is illogical and cannot be answered. Swami Vivekananda in a lecture from 1896 says (Complete Works, Vol 3, Lectures and Discourses, 'The Free Soul' - https://advaitaashrama.org/cw/content.php):
The first argument of the Vedantists against this is that this analysis is not a perfect one. If their Nature be absolute and the soul be also absolute, there will be two absolutes, and all the arguments that apply in the case of the soul to show that it is omnipresent will apply in the case of Nature, and Nature too will be beyond all time, space, and causation, and as the result there will be no change or manifestation. Then will come the difficulty of having two absolutes, which is impossible. What is the solution of the Vedantist? His solution is that, just as the Sankhyas say, it requires some sentient Being as the motive power behind, which makes the mind think and Nature work, because Nature in all its modifications, from gross matter up to Mahat (Intelligence), is simply insentient. Now, says the Vedantist, this sentient Being which is behind the whole universe is what we call God, and consequently this universe is not different from Him. It is He Himself who has become this universe. He not only is the instrumental cause of this universe, but also the material cause. Cause is never different from effect, the effect is but the cause reproduced in another form. We see that every day. So this Being is the cause of Nature. All the forms and phases of Vedanta, either dualistic, or qualified-monistic, or monistic, first take this position that God is not only the instrumental, but also the material cause of this universe, that everything which exists is He. The second step in Vedanta is that these souls are also a part of God, one spark of that Infinite Fire. "As from a mass of fire millions of small particles fly, even so from this Ancient One have come all these souls." So far so good, but it does not yet satisfy. What is meant by a part of the Infinite? The Infinite is indivisible; there cannot be parts of the Infinite. The Absolute cannot be divided. What is meant, therefore, by saying that all these sparks are from Him? The Advaitist, the non-dualistic Vedantist, solves the problem by maintaining that there is really no part; that each soul is really not a part of the Infinite, but actually is the Infinite Brahman. Then how can there be so many? The sun reflected from millions of globules of water appears to be millions of suns, and in each globule is a miniature picture of the sun-form; so all these souls are but reflections and not real. They are not the real "I" which is the God of this universe, the one undivided Being of the universe. And all these little different beings, men and animals etc. are but reflections, and not real. They are simply illusory reflections upon Nature. There is but one Infinite Being in the universe, and that Being appears as you and as I; but this appearance of divisions is after all a delusion. He has not been divided, but only appears to be divided. This apparent division is caused by looking at Him through the network of time, space, and causation. When I look at God through the network of time, space, and causation, I see Him as the material world. When I look at Him from a little higher plane, yet through the same network, I see Him as an animal, a little higher as a man, a little higher as a god, but yet He is the One Infinite Being of the universe, and that Being we are. I am That, and you are That. Not parts of It, but the whole of It. "It is the Eternal Knower standing behind the whole phenomena; He Himself is the phenomena." He is both the subject and the object, He is the "I" and the "You". How is this? "How to know the Knower? The Knower cannot know Himself; I see everything but cannot see myself. The Self, the Knower, the Lord of all, the Real Being, is the cause of all the vision that is in the universe, but it is impossible for Him to see Himself or know Himself, excepting through reflection. You cannot see your own face except in a mirror, and so the Self cannot see Its own nature until It is reflected, and this whole universe therefore is the Self trying to realise Itself.
and later in the same lecture:
Before going into the practical part, we will take up one more intellectual question. So far the logic is tremendously rigorous. If man reasons, there is no place for him to stand until he comes to this, that there is but One Existence, that everything else is nothing. There is no other way left for rational mankind but to take this view. But how is it that what is infinite, ever perfect, ever blessed, Existence-Knowledge-Bliss Absolute, has come under these delusions? It is the same question that has been asked all the world over. In the vulgar form the question becomes, "How did sin come into this world?" This is the most vulgar and sensuous form of the question, and the other is the most philosophic form, but the answer is the same. The same question has been asked in various grades and fashions, but in its lower forms it finds no solution, because the stories of apples and serpents and women do not give the explanation. In that state, the question is childish, and so is the answer. But the question has assumed very high proportions now: "How did this illusion come?" And the answer is as fine. The answer is that we cannot expect any answer to an impossible question. The very question is impossible in terms. You have no right to ask that question. Why? What is perfection? That which is beyond time, space, and causation — that is perfect. Then you ask how the perfect became imperfect. In logical language the question may be put in this form: "How did that which is beyond causation become caused?" You contradict yourself. You first admit it is beyond causation, and then ask what causes it. This question can only be asked within the limits of causation. As far as time and space and causation extend, so far can this question be asked. But beyond that it will be nonsense to ask it, because the question is illogical. Within time, space, and causation it can never be answered, and what answer may lie beyond these limits can only be known when we have transcended them; therefore the wise will let this question rest. When a man is ill, he devotes himself to curing his disease without insisting that he must first learn how he came to have it.
There is another form of this question, a little lower, but more practical and illustrative: What produced this delusion? Can any reality produce delusion? Certainly not. We see that one delusion produces another, and so on. It is delusion always that produces delusion. It is disease that produces disease, and not health that produces disease. The wave is the same thing as the water, the effect is the cause in another form. The effect is delusion, and therefore the cause must be delusion. What produced this delusion? Another delusion. And so on without beginning. The only question that remains for you to ask is: Does not this break your monism, because you get two existences in the universe, one yourself and the other the delusion? The answer is: Delusion cannot be called an existence. Thousands of dreams come into your life, but do not form any part of your life. Dreams come and go; they have no existence. To call delusion existence will be sophistry. Therefore there is only one individual existence in the universe, ever free, and ever blessed; and that is what you are. This is the last conclusion reached by the Advaitists.
It may then be asked: What becomes of all these various forms of worship? They will remain; they are simply groping in the dark for light, and through this groping light will come. We have just seen that the Self cannot see Itself. Our knowledge is within the network of Mâyâ (unreality), and beyond that is freedom. Within the network there is slavery, it is all under law; beyond that there is no law. So far as the universe is concerned, existence is ruled by law, and beyond that is freedom. As long as you are in the network of time, space, and causation, to say you are free is nonsense, because in that network all is under rigorous law, sequence, and consequence. Every thought that you think is caused, every feeling has been caused; to say that the will is free is sheer nonsense. It is only when the infinite existence comes, as it were, into this network of Maya that it takes the form of will. Will is a portion of that being, caught in the network of Maya, and therefore "free will" is a misnomer. It means nothing — sheer nonsense. So is all this talk about freedom. There is no freedom in Maya.
Every one is as much bound in thought, word, deed, and mind, as a piece of stone or this table. That I talk to you now is as rigorous in causation as that you listen to me. There is no freedom until you go beyond Maya. That is the real freedom of the soul. Men, however sharp and intellectual, however clearly they see the force of the logic that nothing here can be free, are all compelled to think they are free; they cannot help it. No work can go on until we begin to say we are free. It means that the freedom we talk about is the glimpse of the blue sky through the clouds and that the real freedom — the blue sky itself— is behind. True freedom cannot exist in the midst of this delusion, this hallucination, this nonsense of the world, this universe of the senses, body, and mind. All these dreams, without beginning or end, uncontrolled and uncontrollable, ill-adjusted, broken, inharmonious, form our idea of this universe. In a dream, when you see a giant with twenty heads chasing you, and you are flying from him, you do not think it is inharmonious; you think it is proper and right. So is this law. All that you call law is simply chance without meaning. In this dream state you call it law. Within Maya, so far as this law of time, space and causation exists, there is no freedom; and all these various forms of worship are within this Maya. The idea of God and the ideas of brute and of man are within this Maya, and as such are equally hallucinations; all of them are dreams. But you must take care not to argue like some extraordinary men of whom we hear at the present time. They say the idea of God is a delusion, but the idea of this world is true. Both ideas stand or fall by the same logic. He alone has the right to be an atheist who denies this world, as well as the other. The same argument is for both. The same mass of delusion extends from God to the lowest animal, from a blade of grass to the Creator. They stand or fall by the same logic. The same person who sees falsity in the idea of God ought also to see it in the idea of his own body or his own mind. When God vanishes, then also vanish the body and mind; and when both vanish, that which is the Real Existence remains for ever. "There the eyes cannot go, nor the speech, nor the mind. We cannot see it, neither know it." And we now understand that so far as speech and thought and knowledge and intellect go, it is all within this Maya within bondage. Beyond that is Reality. There neither thought, nor mind, nor speech, can reach.
Nice question, and not as easy to answer as one might think. I was struck by the following passage :
Monotheists say the number of gods is 1....[T]he main way of arguing for the existence of exactly one god includes the assumption that to be a god is to be maximally perfect. Thus x is a god iff x is more perfect than (is greater than) every other possible thing. Monotheism directly follows from the thesis that maximal perfection is uniquely instantiated. For any x and any y, if x is a god and y is a god, then x and y are each greater than every other possible thing. The only way for this to make sense is for x to be identical to y. Hence there is exactly one god and this god is God.(Eric Steinhart, 'On the number of gods', International Journal for Philosophy of Religion, Vol. 72, No. 2, Logic (October 2012), pp. 75-83; 78.)
This does not directly answer your question but it leads the way to it. If there can be only one maximally perfect being, it follows that anything, Φ, that God creates cannot be maximally perfect. It must be, in your terms, 'less' than Godself or 'imperfect'.
I don't think it follows without further argument - extra premises - that what is imperfect is necessarily 'evil' in the sense of 'not [being] able to obey God of itself'.
I should have thought that the omnipotent God - omnipotent because perfect - would be able to create imperfect beings (Φs) that were, because God had conferred the inherent power on them, to obey God 'of themselves'. This is logically possible whether or not it squares with the main monotheistic traditions.