Summa contra Gentiles3.153 Chapter CLIII. That divine grace causes hope in us

In the same way it can be proved that grace must needs cause in us the hope of future bliss.

Because the love which a man has for others, arises from his love for himself, inasmuch as a man looks upon his friend as his other self. Now, a man loves himself, in that he wishes good for himself; even as he loves another, in that he wishes good for him. Consequently, a man through having an affection for his own good, is led to have an affection for another’s good. So that when a man hopes for a good from another he is on the way to love him in himself, of whom he hopes some good: for a man is loved in himself, when the lover wills his good, even though he gain nothing from it. Wherefore, since sanctifying grace causes man to love God for himself, the consequence is that grace also causes man to hope in God.—Friendship whereby one loves another in himself, although it be not for one’s own profit, nevertheless turns to one’s profit in many ways, in so far as one friend helps another as he would help himself. Consequently, when one man loves another and knows that he is beloved of him, the result is that he has hope of him. Now, grace makes man a lover of God, according to the love of charity, so that at the same time he knows by faith that God already loves him, as expressed by the words of i Jo. iv. io: In this is love: not as though we had loved God, hut because He hath first loved us. The effect, therefore, of the gift of grace is that man hopes in God.—Hence it is evident that, as hope prepares man for true love of God, so conversely by charity man is strengthened in hope.

Moreover. There arises in every lover the desire to be united as far as possible with the beloved: hence nothing gives greater pleasure to friends than living together. Since then grace makes man a lover of God, it must also ma him desire union with God, as far as this is possible. Mow faith which originates from grace, affirms it to be possible for man to be united to God in perfect enjoyment wherein beatitude consists. Wherefore the desire of this enjoyment arises in man from his love of God But the desire of a thing troubles the soul of the desirer unless he have the hope of obtaining it. Accordingly, as grace gives rise man to the love of God and faith, it was fitting that it should also give rise to the hope of obtaining beatitude the life to come.

Again. If any difficulty offers itself to those who are emg directed to an end desired by them, they are comforted by the hope of obtaining it: thus one puts up with the bitter medicine through the hope of being restored to health Now, many difficulties have to be faced on the way in which we fare towards beatitude, that is the bourn of all our desires: since virtue, which is the road to beatitude, is about difficult things. In order, then, that man might tend to beatitude with a fighter heart and greater readiness, it was necessary to give him the hope of obtaining beatitude.

Further. No man is moved towards an end which he deems impossible to obtain. Hence that a man may proceed towards a certain end, it is necessary for him to think of that end as something possible for him to have: and this thought is afforded by hope. Since, then, man is directed by grace to the last end which is beatitude, it was necessary for the hope of obtaining beatitude to be engraved on man's thoughts by grace. Hence it is said (1 Pet. i. a, 4): Who... hath regenerated us unto a lively hope. unto an inheritance incorruptible... reserved in heaven: and (Rom. viii. 24): We are saved by hope.