Proverbs 6:1-5: "My son, if you have put up security for your neighbor, have given your pledge for a stranger, if you are snared in the words of your mouth, caught in the words of your mouth, then do this, my son, and save yourself, for you have come into the hand of your neighbor: go, hasten, and plead urgently with your neighbor. Give your eyes no sleep and your eyelids no slumber; save yourself like a gazelle from the hand of the hunter, like a bird from the hand of the fowler."
A loan guarantee, in finance, is a promise by one party (the guarantor) to assume the debt obligation of a borrower if that borrower defaults. A guarantee can be limited or unlimited, making the guarantor liable for only a portion or all of the debt.
The book of Proverbs issues a strong warning in chapter 6 to cosigning on loans/debt. While intentions might be good on both sides, you might actually be encouraging folly or foolishness on behalf of the guarantee and putting yourself under extreme risk.