Crouching demon, hidden danger

In the New American Bible translation of today’s first reading (Genesis 4:1-15, 25), the Lord gives this evocative warning:

Why are you so resentful and crestfallen?

If you do well, you can hold up your head;
but if not, sin is a demon lurking at the door:
his urge is toward you, yet you can be his master.

The English Standard Version puts it thusly:

Why are you angry, and why has your face fallen?

If you do well, will you not be accepted?
And if you do not do well, sin is crouching at the door.
Its desire is for you, but you must rule over it.

However it is translated, the basic warning is plain: we must not let resentment and anger remain within us, hidden or otherwise, lest these feelings lead us into deadly sin.

Rather, we need to open our minds and our hearts to the light and love of Christ, so that the Lord may heal whatever hurts we may suffer and that he may enable us always to walk in the paths of righteousness, charity, and true peace.