The word usually translated as “evil” in the NT is poneros which means “burdened with toil.” The opposite of burdens in Christ’s teaching is “blessings” which is makarios, which means “happy” or “fortunate.” The major blessings are listed in the Beatitudes.
The Bigger Picture
Christ divides the world into physical, social, and spiritual (interior, personal). This division describe the way humans perceive their world and perceive God in the world. God created the natural physical world. Christ comes to reform the social world, created by man, with the Kingdom of Heaven (universal rule). The Spirit, through the universal rule, privately moves the inner, personal world of individuals. Using this logic, the Trinity is not a division in God, but simply a division in how we perceive God acting in the world.
In this division of the world, our burdens and blessings don’t come from the natural, social, or spiritual world, but from the way we choose to interact with it.
On an individual level, these three realms translate into our physical needs, intellectual needs, and spiritual needs. All of these needs can be either a source of blessings or burdens. Christ (unlike John the Baptist) seldom speaks against our physical needs. Indeed, he teaches that these physical needs only become a burden when people make them more important than they are, either by denying them or by getting lost in them.
Since Christ’s focus is social, he often speaks against our “intellectual” needs to be accepted by society. This is clearly the biggest burden in society. His teaching was meant to relieve us of this burden.
On the spiritual level, Christ always talks about spirit in terms of emotions, here, the emotion of love. These emotions also can be a burden or a blessing. Here, love can take us toward God and is be a blessing. However, if we let our caring for our families become more important than what is good, that same caring becomes burden.
First, Christ came to put our suffering in this life into a large perspective. Our temporary suffering in this life is not only temporary, but it serves a purpose. Christ came to awaken us to that purpose and the meaning of human suffering. As certain physical constants in the universe are necessary for life to exist, evil and suffering are necessary conditions for a meaningful life. Christ is truly saying what he means: though suffering is necessary we can be cleanse of its burden.
There are two kinds of evil: suffering cause by nature (sickness, disaster, death), the kind of suffering that Christ is dealing with here, and evil caused by the actions by humans. If evil actions by humans were not possible, we would have no meaningful choices. If no suffering (ours or that of others) resulted as consequence of our decisions, all choices would be equally good and therefore meaningless. First, Christ wants us to be cleanse of our misconceptions that by doing evil we can somehow gain from it. Any short-term gain becomes a long-term loss.
This brings us to the suffering Christ is addressing here, the suffering that is cause by the nature of things, disease, aging, and eventual death. If there were no natural suffering, we would have no reason to care for one another and no incentive to learn more about the world and how it works. Awareness of death itself puts our life into a greater perspective. As Christ says in the Beatitudes, those who mourn on being "summoned," summoned to a greater awareness.
Christ wanted us to focus on what our suffering demands of us: caring for one another and learning about the world. Like children complaining that their parents won’t let them eat candy for every meal, we have to realize that this world has suffering of both types as necessary conditions for our freedom and growth. Christ wants us to be cleansed of our misconceptions about life. He wanted us to realize that our choices involve real freedom and real consequences.