We are prone to define the "blessed life" as one which we must achieve for ourselves. The Beatitudes re-frame our definition of blessing away from us achieving on our own, and instead point us to the blessed life as one which we freely receive through the merits of Christ.

We don't embody/do the Beatitudes (so we don't deserve blessing).

Christ did embody/fulfill the Beatitudes perfectly on our behalf.

Therefore, we can be blessed (and live the blessed life).