We cannot consider the Sefirot or attributes as blind forces, like those of nature.
They are each of them self-motivating, each functioning within itself and purposeful in its action.
Nevertheless, they are not isolated and structurally separate.
On the contrary, Gevurah can be a vehicle of Chesed and Chesed can be an instrument of Gevurah.
It is essential for them to work in combination in order for the world to exist.
They are bound to one another at the root, growing out of the same source, and there is no essential contradiction between them.
We seem to be touching on the idea behind certain contradictory phrases such as: "I form the light and the darkness. I make peace and create evil" (Isaiah 45:7).
The common factor in this notion of the same God making both good and evil is not to deny that they are separate and opposite elements.
Each operates separately, has its own rules and guidelines, and is in essential opposition to the other.
The fact that Gevurah can be a vessel for Chesed only shows that both grow out of the same root.
In human life, too, one can point to such combinations of Chesed and Gevurah being channels for one another.
If parents give children all they desire, as an act of Chesed, this benevolence (spoiling the children) can turn into a great evil, a concealment of Divine grace.
On the other hand, the response to an act of punishment can be one of grace and goodness, Chesed, not only in terms of results, but even in terms of feeling.
It has been sarcastically remarked, for instance, that the punishment of the serpent in the Garden of Eden was really a great gift, because if he can live from the dust of the earth, he doesn't have to strive to make a living — he has all that he requires and lacks nothing.
The answer to this is that this is precisely the forcefulness of the judgment of God upon the serpent:
I give you all the food in the world to eat, and you can go to perdition—I do not want you to turn to me for anything more.
So that the Gevurah aspect of Chesed and the Chesed aspect of Gevurah are very much interwoven and interdependent.
Everything in our world is a combination.
The attributes grow out of one root, and there is no such thing in man as a pure manifestation of Gevurah or Chesed or any other attribute.
Each manifestation is mixed.
In nature, of course, it is different, and we readily distinguish between specific forces of attraction and repulsion and the like, and observe how objects change their location and creatures their habits according to definite, if blind, mechanical influences.
–Rabbi Adin Steinsaltz
From The Sustaining Utterance by Rabbi Adin Steinsaltz