Pro 11:15 He that is surety for a stranger shall smart [for it]: and he that hateth suretiship is sure.
I strongly urge you to never co sign for anyone. It will end up being one of your biggest regrets in life. No matter how sincere the other party is, when things go south, they will not give a second thought about saving themselves and hanging you out to dry.
It may seem hard, but the Lord is not making a suggestion here, but giving us a valuable principle. To ignore it will cost us dearly, to obey itwill bring safety.
I pray this blog finds fertile soil and will save someone the heartaches we have experienced because we tried to help someone who gave us many assurances and yet went back on their word. God's Word says what it means and means what it says.