First, from John Calvin in his Institutes of the Christian Religion (3.25.10)...
If God contains the fullness of all good things in himself like an inexhaustible fountain, nothing beyond him is to be sought by those who strive after the highest good and all the elements of happiness… If the Lord will share his glory, power, and righteousness with the elect – nay, will give himself to be enjoyed by them and, what is more excellent, will somehow make them to become one with humself, let us remember that every sort of happiness is included under this benefit.Then this, from Augustine in The City of God (XXII.30)...
True peace shall be there, where no one shall suffer opposition either from himself or any other. God himself, who is the Author of virtue, shall there be its reward; for, as there is nothing greater or better, He has promised himself. What else was meant by His word through the prophet, “I will be your God, and ye shall be my people,” than, “I shall be their satisfaction, I shall be all that men honorably desire” – life, and health, and nourishment, and plenty, and glory, and honor, and peace, and all good things? This, too, is the right interpretation of the apostle, ‘That God may be in all.’ He shall be the end of our desires who shall be seen without end, loved without cloy, praised without weariness. This outgoing affection, this employment, shall certainly be, like eternal life itself, common to all.And finally, from the Heidelberg Catechism (Q&A 58)...
What comfort do you derive from the article of the life everlasting?May these truths increase in us a hunger for holiness today and a longing for the Lord's return. Come, Lord Jesus!
That, since I now feel in my heart the beginning of eternal joy, after this life I shall possess perfect bliss, such as eye has not seen nor ear heard, neither has entered into the heart of man - therein to praise god forever.