Psalm 16:3

As for the saints in the land, they are the excellent ones, in whom is all my delight.

Psalm 16:11

You make known to me the path of life; in your presence there is fullness of joy; at your right hand are pleasures forevermore.

Thomas Aquinas, Summa Theologica (I-II Q4 A8):

If we speak of the happiness of this life, the happy man needs friends, as the Philosopher says [Aristotle?], not, indeed, to make use of them, since he suffices himself; nor to delight in them, since he possesses perfect delight in the operation of virtue; but for the purpose of a good operation, viz., that he may do good to them; that he may delight in seeing them do good; and again that he may be helped by them in his good work. For in order that man may do well, whether in the works of the active life, or in those of the contemplative life, he needs the fellowship of friends.

But if we speak of perfect Happiness which will be in our heavenly Fatherland, the fellowship of friends is not essential to Happiness; since man has the entire fullness of his perfection in God. But the fellowship of friends conduces to the well-being of Happiness. Hence Augustine says that the spiritual creatures receive no other interior aid to happiness than the eternity, truth, and charity of the Creator. But if they can be said to be helped from without, perhaps it is only by this that they see one another and rejoice in God, at their fellowship.