5 Wherefore, my beloved brethren, I beseech of you in words of soberness that ye would repent, and come with full purpose of heart, and cleave unto God as he cleaveth unto you. And while his arm of mercy is extended towards you in the light of the day, harden not your hearts.
What does it mean to "cleave unto God?" How does he cleave unto us?
The word "cleave" isn't used much as an intransitive verb in modern English. It is a Germanic word from Old English that means to adhere closely, stick, or cling. The German word is kleben and means to stick. It is also used to mean remain faithful. As we remain faithful to God -- as we adhere closely to the commandments and thus to Him -- He promises to remain faithful to us.
What seems curious to me is that the general modern use of the word is in connection with division. You can cleave a gemstone or a piece of wood along the natural lines of division in the crystal or the wood. But there is no natural line of division between us and God. We create the dividing line. Verse 4 of this chapter says:
4 And how merciful is our God unto us, for he remembereth the house of Israel, both roots and branches; and he stretches forth his hands unto them all the day long; and they are a stiffnecked and a gainsaying people; but as many as will not harden their hearts shall be saved in the kingdom of God.
He remembers us always and His hands are always outstretched. We withdraw from Him. He never withdraws from us.
Jacobs postscript is "O be wise; what can I say more?" (v. 11)