Ok, I know some of you may be asking yourself how "intended purpose" is connected with "good and how I can justify that connection. I would have to say that your question would be more appropriately asked, How is "created purpose" connected to something being "objectively good/bad"? The answer is quite simple. In order to measure anything, it requires some kind of objective standard to base that measurement. How do we know which way is true, grid, or magnetic north? We can objectively determine which way is north by using objective standards such as the magnetic poles, north star, GPS, ect. Now, lets say we took that objective standard away. Lets say we are floating in the vacuum of space. Which way is north then?
Although it may not be perfect, "created purpose" is the only objective standard (that I can think of anyway) to measure a thing's goodness. You see, anyone can determine something to be good/bad for various reasons. Sometimes what is "good or bad" is not "black and white". Without an objective standard of measure, good/bad can be rather difficult to determine.
My "painbot" example is the best could come up with to explain this. I know it is not perfect....but eh.
Lets say a man invented a robot. This robot was created with intelligence, feeling, hopes, dreams, emotions, and anything else you would expect a living individual to possess. However, this inventor created this robot for the sole purpose of inflicting pain and suffering onto it and called it a "painbot". (I know this sound twisted but bare with me.) Thus, the created purpose of a "painbot" is to suffer. Thus, the "painbot's" pain and suffering would be objectively good because it fulfills its created purpose. If a painbot was unable to experience pain and suffering, it would defective and rejected. Because for the painbot, joy and pleasure would go against a painbot's created purpose thus making joy and pleasure objectively bad.
Now you may say, "That is sick. Why would anyone be so twisted as to creating painbots?" That still does not change the fact that a good quality painbot is one who suffers greatly and a poor quality painbot is one who does not. All you have done is made the motive for the creation of painbots and the painbots themselves subjective but the actual purpose still remains objectively unchanged.
Lets say the inventor was a psychopath. Lets say he built hundreds of painbots so that himself and many other psychopaths could inflict pain and suffering on a machine rather than another human being. As a result, hundreds of human lives were saved because of it? Some may then say that painbots are good. Lets say that there was a supreme authority above all who created a law that prohibited the creation of painbots. That would make the motive and existence of painbots objectively bad. Yet it still does not change the objective fact that the level of pain and suffering a painbot experiences objectively determines how good or bad that painbot is.
You might be wondering, what does this have to do with a God. Well, I am not sure how it would work out in polytheism, but in monotheism (especially in regards to the God of Abraham) it is critical. Because if the God of Abraham is the one true God. That God is an eternal being who was never created and thus has no "created purpose". Being that this God has some level of intelligence, He is capable of bestowing a purpose onto Himself. However, because He as no equal to make that purpose subjective nor anyone above to make that purpose "objectively bad", whatever purpose He bestows upon Himself is "Objectively Good" by default! As a result, the purpose of all His creations will be "objectively good" by default. So in conclusion, assuming the God of Abraham is the one true God and not another, anything that a creation does that goes against God's created purpose is "absolutely bad" and anything that agrees with God's created purpose is "absolutely good".
