So many, many things there are

So many, many things there are
To which the keys are lacking;
Deep silence answers all man’s knocks
And foils his undertaking.

Thou human heart! There sorrows howl
As wolves, by hunger driven,
And yet that same heart, oh, my God!
To love alone is given.

’Tis capable of so much love
That man’s wit may be failing,
And he may as the lonely dove
In vain roam, ever wailing.