Opposites, or so they seem, can both be true.
Smeagol-Gollum best captures our nature as humans. The one-and-the-same character from Lord of The Rings is a picture of the internal struggle we all face. Explaining our Smeagol-Gollum nature to students over many years, I teach two “D” words: dignity-depravity. I hyphenate the two terms to suggest that they are one-and-the-same within all of us. We protect life because all people are conceived with worth, value, and dignity. We protect people from other people because all people are also conceived with inherent corruption, disobedience, and sin. Both protections are true at the same time.
Smeagol-Gollum expresses the truth: humans are great and great sinners.
But some do not like to be called “sinners.” Their view of humanity resides more in a side-by-side comparison. In Eastern thinking “yin-yang” fosters a give-and-take mentality. In this view humans are not totality any one thing. There is an ebb-and-flow to life. Sometimes we are good, sometimes we are bad. Others would want to use the word “balance” to denote our nature. If we could just find the right balance, live the balanced life, sustain a daily balance, we could achieve our better humanity.Instead of so-called “balance” I have encouraged my students over the years to regard “tension” as the appropriate metaphor for how we should think about ourselves and life. I draw two arrows pointed at each other on the board, writing the word “tension” in between the two points. Two ideas can be true at the same time without full human understanding.
We hold seeming opposites as both true at the same time.
In theology, for instance, the tension-filled-pairs cited here only scratch the surface:
Divine sovereignty—human responsibility
The German theologian Karl Barth explained tension this way:
If we are to think about life, we must penetrate its hidden corners, and steadily refuse to treat anything—however trivial or disgusting it may seem to be—as irrelevant. To be sincere, our thought must share in the tension of human life, in its criss-cross lines, and in its kaleidoscopic movements. And life is neither simple, nor straightforward, nor obvious. 
Raphael’s famous “School of Athens” painting well symbolizes the concept of tension. Plato and Aristotle (center of painting) represented idealist and realist perspectives, the one thing and the many things. Both are “true.” Both are necessary. The philosophical relationship is a visual reminder that all points of view must be heard, understood, mediated, and ultimately corralled into coherence.
Do I believe it is impossible to know anything for certain? Of course not. Do I believe surety is beyond human ability in this life? Of course not. Do I believe that mystery is the last word in theology. Of course not. What I do believe is that our humanness limits our ability to fully comprehend anything. A key distinctive between God and man lies in our finitude. If we could understand and explain everything, we would be God. So, in this life we sometimes hold two, seemingly contradictory ideas, in tension.
The best physical example of tension is the placement of a keystone in a stone arch. When a stone arch is built, normally a wooden template is placed as the center around which the stones are cemented. As both sides of the arch are about to meet, a keystone is inserted as the connection, holding both sides together. Tension makes an arch possible.
Tension teaches a number of crucial ideas:
Knowledge is accessible, understanding is possible, but belief is essential
Certainty is possible based upon one’s belief
Guarantee of certainty is often mediated by unintended consequences
Humility is the essence of human knowledge, conditioning certainty
Charity to our neighbor is our response when our certainties disagree
Loyalty to our belief does not negate charity
Charity is a demonstration of true dialogue: two beliefs heard
Smeagol regains and retains his personhood over Gollum Lord of The Rings: Return of The King. The tension we feel now will someday be obliterated. In the mean time, care for people should give us focus, care in decision making should give us pause. While I do know many things, saying “I don’t know” is, at times, the best response I can give. But what I know for sure is that I may hold what seem to be opposites, in tension.
“Jesus was delivered up according to the definite plan and foreknowledge of God, you crucified and killed by the hands of lawless men” (Acts 2:23, ESV). In the same verse, divine sovereignty and human responsibility, both true, held in tension. Dr. Eckel teaches tension for Capital Seminary and in every other venue.
 Some Scriptural examples of tension-filled-pairs: Exodus 8:15 with Exodus 7:3; Isaiah 45:7 with Habakkuk 3:2; John 1:29 with Revelation 5:5; John 6:37 with John 6:44; Isaiah 9:6-7 with Matthew 10:34.
 Karl Barth, The Epistle to the Romans. 6th ed. (Oxford): 425.