Filling the void
Our Gospel reading today is a reminder that we cannot serve two masters. "Whoever is not with me is against me," Jesus said. Likewise, whoever is with Jesus is fighting against the strategies of Satan. There is no middle ground. We are not living fully in God if we're rejecting, for example, a moral teaching of the Church, no matter how inconvenient or difficult it is to obey.
The moral relativism rampant in our world today has infected many Christians. However, there is no neutral corner where it's safe to make up our own minds about what is right and wrong so that we can do whatever we want, then go to Mass on Sunday to earn points with God, then return to a life that's contrary to the teachings of God.
(A side note: If we think that any of the Church's teachings on moral issues are outdated or unreasonable, it's because we haven't actually read them and looked for the love that's at the core of each teaching.)
If we refuse to imitate Jesus, even for one moment, God won't force us to obey him and serve him, but the devil won't be so kind. Our Christian inactivity -- our lack of Christ-like living -- is a void that demons seek to fill.
When we clean sin from our lives, we must fill our lives with the Lord, doing what he wants to do through us, saying and dreaming and planning and serving as he would do if he were in our shoes (for he does want to walk with us in our shoes). Otherwise, we're an open door for temptation.
Christians are "little Christs"; we are the presence of God in the modern world. Whatever we do that works against this calling is what makes our hearts become a kingdom that's divided against itself. Do you feel divided?
We all have temporary relapses back to our pre-baptismal sinful nature. The Church offers a cure for this: the Sacrament of Reconciliation and the penance rite at the beginning of each Mass. If we truly want to be with Christ and not against him, we avail ourselves of this cure and we're grateful for it.
We need to honestly examine our lives to seek out the places where we have left a void. What Christ-like deed have we been reluctant to do? What sin are we enjoying too much to quit? What teaching of the Church is too difficult to trust and embrace?
We cannot draw a line and say that we don't need to imitate Christ farther than this. Yet, we often rationalize: "I can't be expected to live that way! Only a saint could do that. I'm an ordinary Christian."
There is no line. There is only a choice between Christian activity and a void that makes room for evil. The good news is that we have but to decide in favor of Christ and he rushes to our aid. God graces us with the ability to do whatever he asks of us.
Deciding in favor of keeping a void means we're tempting demons to come and take advantage of us. And you know how poorly demons resist temptation! They return the favor by tempting us. But the busier we are doing the Lord's will, the less we have time to notice, let alone give in to, their temptations.