​1 John 2:15

• 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. (1 John 2:15)

This, I would argue, is another instance of a verse that can be misconstrued as referring to what we can see on the outside of a Christian.  That it's referring to their flesh, something that we can convince ourselves can be, and sometimes is, easy to judge.  However, if one interprets this verse from the perspective that a born-again spirit is holy while the corresponding flesh remains unholy, it makes even more sense, because we, through our own experiences and observing others, see that no one is perfect in the flesh or outwardly perfectly hates the world, so there must be exceptions or something else must be going on, if we believe the scripture.  I elaborate on this further here (showing instead there is a polar contrast between the holiness of a born-again spirit and unholiness of the flesh), from teachings I learned from others which reconcile the most scriptures out of all the competing ideas I've heard, and have the most overall scriptural supp0rt.

Long story short, the love of the Father is in the born-again spirit, which we can't see:

• That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. Marvel not that I said unto thee, Ye must be born again. The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit. (John 3:6-8)

But we're often tempted to judge on what we can see, the flesh.