Proverbs 18:24 contains one of the most significant statements about friendship in wisdom literature: "There is a friend that sticketh closer than a brother." The Hebrew dabaq — "sticketh" — is the same word used in Genesis 2:24 for a husband clinging to his wife in covenant. This is not casual affection. It is the language of covenantal loyalty applied to friendship. The verse also acknowledges the inverse: "A man that hath friends must shew himself friendly" — not all who present as friends will prove to be this kind.
The end of the friendship between Jonathan and David — though separated by death rather than betrayal — is one of Scripture's most tender friendship portraits. David said Jonathan's love to him was "wonderful, passing the love of women" (2 Samuel 1:26). He lamented Jonathan publicly, in a formal elegy. The grief of losing a close friend has scriptural precedent at the highest register.
Commentary is from a charismatic Protestant perspective, drawing on KJV text and public-domain sources including Spurgeon, Andrew Murray, and Matthew Henry.