I write to you, young people, because you are strong and the word of God abides in you, and you have overcome the evil one. Do not love the world or the things in the world. The love of the Father is not in those who love the world; for all that is in the world—the desire of the flesh, the desire of the eyes, the pride in riches—comes not from the Father but from the world. And the world and its desire are passing away, but those who do the will of God live forever. (1 John 2:14-17, NRSV)
I have written unto you, young men, because ye are strong, and the word of God abideth in you, and ye have overcome the wicked one. Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him. For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world. And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever. (1 John 2:14-17, KJV)
Two equations, c/o the elder:
(1) Love of God = good.
(2) Love of the World = evil.
The elder doesn't mean that God's creations (trees, birds, flowers, and all that good stuff) are bad. It's the people of the world who turn away from God and become obsessed with things like sex, beauty, and money.