The Beatitudes take up and fulfill God’s promises from Abraham on by ordering them to the Kingdom of heaven. They respond to the desire for happiness that God has placed in the human heart.
The Beatitudes teach us the final end to which God calls us: the Kingdom, the vision of God, participation in the divine nature, eternal life, filiation, rest in God.
The beatitude of eternal life is a gratuitous gift of God. It is supernatural, as is the grace that leads us there.