In Trinitarian terms, perhaps we might say that God the Father is supremely the guarantee that God does not lose control over his giving. He gives himself in his Son and his Spirit, but he, in his own Person, remains always the giver even in his given-ness.
It is different for us. We can hardly give ourselves without giving ourselves away. To give ourselves is to lose ourselves; ultimately, the martyr loses himself - gives himself away. But it is so in every little act of love. We give ourselves, and in giving we lose ourselves. We give ourselves away. We are conditioned by our giving. We diminish.
That is why the only key to radical self-giving is the remembrance that we are in the hand of the God who holds onto us even as we give ourselves away, and regathers all of the pieces of us that we have - at his command! - freely distributed and scattered throughout our lives in acts of self-giving love (and indeed without his command, in sinful acts of illegitimate attachment). Without the promise that he, the giver who is not given away, holds onto us, how can we dare to give ourselves away?
Without the resurrection, how could we dare to let go of ourselves?