Commentaries:
In these three verses, the concept of faith continues. For us, most important is "even though the outward man is perishing, yet the inward man is being renewed day by day." What is Paul describing here? It is the process of dying and renewing. The outer man—the shell, the body—is decaying. What causes it to decay? In the context, it is the trials of life—the perplexities, the afflictions, the persecutions, the solitude.
The outer man is decaying through the trials of life, while the inner man is being strengthened through the same trials. The energy of the body is spent in doing God's will, and it is being transformed into the energy of the spirit. Moses was so energized that Deuteronomy 34:7 says that at the age of 120, his natural forces, his vigor, were not abated.
We are aware of this principle because transformations of energy take place all around us every day. Energy from the sun strikes the earth, and plants transform that energy into leaves, flowers, and fruit. The energy of a river can be transformed into electricity, which in turn is transformed into light and heat—one form of energy turned into another.
Paul is saying that, if we yield to God, though it expends our physical energy, it will be transformed into Christ's likeness. We will become like Christ. The key is to expend our energy in doing the will of God, otherwise the right fruit will not be produced. Even though we have to sacrifice ourselves in doing it—we give up our time, our energy, our resources—what will be produced is spiritual energy. Our physical energy will be transformed into the beauty and power of the spirit until death, and then the resurrection will release the full power of the spirit. All along the way, the fruit of that process will be true conviction because we will know God.
We Christians have this treasure in earthen vessels. If we submit to God's discipline—expending ourselves and yielding to God in the little things day by day—we will see our conviction grow. Then, if people call us into account, we will not be worried because we know absolutely—because we have lived it. This is the kind of faith God wants us to have.
John W. Ritenbaugh
Conviction, Moses, and Us
Faith is the confidence we have in possessing the things we hope for because of the promises of God. Faithfulness is adhering unswervingly to God and His covenant. To be faithful we need to be loyal (steadfastly affectionate and allegiant to God), conscientious (scrupulous in doing God's will), dedicated (zealously devoted to God), and truthful (true to God's Word and standard of righteousness).
Martin G. Collins
Faithfulness
Other Forerunner Commentary entries containing 2 Corinthians 4:18:
Genesis 25:34
Leviticus 23:24-25
Psalm 39:5
Matthew 6:19-20