What Kind of Contract is This?

I just watched the Reverend Franklin Graham, Billy Graham's son, talk about hell and explain that if we do not accept Christ as our savior we will burn forever. I have spent my whole adult life dealing with lawyers and the legal system and if I have learned one thing it is that a contract entered into under duress is not binding nor enforceable. So how can we willingly enter into a binding and enforceable contract with God if we are threatened that failure to do so will result in horrific consequences? I guess God couldn't find a lawyer in heaven to write the contract, right?