The counsels of God called ‘conditional’, that is, by which he has ordained to do something on the condition that his creatures execute such and such a commandment, are so determined that the outcome of them depends upon the execution or non-execution of the given condition. Such is the one by which he ordained to render the happiness of the first man perpetual, this is, if he continued to persevere in his integrity. So also was that decree by which he concluded to give the people of Israel a perfectly happy life in the land of Canaan, that is, if they observed completely the law that he had given. Moreover, in a similar fashion he has ordained to save all men by our Lord Jesus, that is, if they do not demonstrate themselves to be unworthy through unbelief. Therefore in these kind of counsels, the certainty of the execution of the condition determines necessarily the certainty of the fulfillment of the counsels themselves. And in the same way the knowledge which one might have of the certainty of the one depends upon his knowledge of the other. Because God, as we have said above, knew certainly the faculties of man and knew exactly to what extent they would resist temptation to evil, he also knew certainly that man would fall from his integrity and that consequently the condition of his perpetual blessing would not be fulfilled. The corruption of sin having then expanded over the whole human race and the law requiring a perfect sanctity, he saw also that it was impossible that. Israel could fulfill the law and impossible therefore that his counsel touching the happiness of Canaan succeed. And this corruption having already so spread in man that it has infected of all his faculties to the very bottom and has rendered him totally unable to believe in the Redeemer unless God himself forms faith in his heart, God foreknows certainly and undoubtedly who will be saved because he has resolved to provide for them to believe, and who will not believe because he has ordained not to undertake in the same way for them. Thus, with respect to God, the knowledge of the outcome is clear and infallible.
With respect to men it is otherwise. If God was content to offer the grace of salvation only externally, considering the condition in which we are all born, it would be easy to predict that it would be universally rejected. It is not difficult to say that the sun will not be known in a land where all that inhabitants are blind. But because God has elected some and forsaken the others, and because he has not revealed to us who these are in particular or shown their names written in his register, no one can be completely assured that even his neighbor is saved, in so far as he does not know if he is among those to whom it will be given to truly believe. This follows the statement of the Apostle, that ‘God knows those who are his.’ (II Tim 2:19).
With respect to those counsels that are commonly called ‘absolute,’ that is, by which God out of his pure will resolves to do something without having regard for any condition whatever the outcome of it is absolutely certain. And God knows that it will occur, not because such, and such a condition should certainly precede it but because be has resolutely determined to do it.
Moyse Amyraut, “Brief Treatise on Predestination and its Dependent Principles,” trans., by Richard Lum Richard. Th.D. diss, 1986, 65-66. [For more on this subject in all its complexity and nuance, go here.]