Treatise on Grace Chapter 1 -Whatever Christ intends by the terms flesh and spirit in the words, yet this much is manifested and undeniable, that Christ here intends to shew Nicodemus the necessity of a new birth, or another birth than his natural birth, and that, from this argument, that a man that has been the subject only of the first birth, has nothing of that in his heart which he must have in order to enter in the kingdom. He has nothing at all of that which Christ calls spirit, whatever that be.