In his Encyclical on Moral Theology, St. John Paul II cautioned against falling into the theological loophole that is commonly called the “fundamental option.”  The general idea of the fundamental option is that each person makes a basic choice to love God and as long as they do not consciously revoke that decision, they remain in His good graces.  In this way it becomes little more than a psychological game where as long as we say we love God, it is so.  Our actions do nothing to change our fundamental stance as long as we still “love” God in our minds.  With the adoption of this viewpoint throughout the Church, the idea of mortal sin has been lost and many people miss out on the opportunity to bathe in God’s merciful love.

Despite this, the Church still teaches that there is such thing as mortal sin and a single mortal sin can damn us to hell for all eternity.  The Catechism says “[T]o die in mortal sin without repenting and accepting God’s merciful love means remaining separated from him forever by our own free choice” (CCC 1033). While this constitutes a truth of the faith, it is fruitful to look at why this is the case.  All too often people will view this teaching as “fire and brimstone” but it can have a bearing on our daily lives, especially those who truly want to love God.

There is a subtlety in the quote from the Catechism that is easy to miss. The choice of describing it as being in mortal sin, rather than “having committed mortal sin” or “with mortal sin on his soul,” reveals a deep anthropological truth and shows us how sin is more than just an offense against God.

Man, because he is free has the freedom for self-determination.  Man can become whatever he wants to become.  Now, this is not meant in a “you can do anything if you just believe in yourself” kind of way.  Instead it means that we are free everywhere and always to be a certain kind of person.  A man who desires to be honest, is always free to do the honest thing.  A man who desires to humble, always has the power to do the humble thing.  It is only on this level that man is authentically free and thus responsible.  Where the self-determination comes in is that by repeatedly performing acts of honesty or humility the man becomes honest or humble.  These habitual dispositions (we call them virtues) become almost second nature to us.  In other words, our actions determine the kind of person we are.  This can also work for woe.  The man who repeatedly lies out of fear becomes a liar and coward.

When we speak of heaven then we must first admit that there are only certain kinds of people that are fit to be admitted.   We shall return to the question of why it must be a certain type, but first it is necessary to make a further distinction.  While self-determination plays a key part in this, it is not the only thing (or even the most important thing).  The most important thing is whether the heaven life is alive in our souls.  Because God is “a consuming fire” we cannot enter into eternal friendship with Him without being “equals” with Him.  This is so important to understand any time we speak of Heaven or Hell.  Not everyone could stand in God’s Presence.  He gives us sanctifying grace to make us fireproof.  Without it, no matter how many good things we have done, the fire of His love would be more painful than the fires of Hell (this is why we can say that Hell is a sign of God’s mercy).

What this means is that this time of trial and testing is all about being made fit.  We must do everything in our power to keep the life of God that was freely given to us in Baptism (ordinarily) coursing through our souls.  This is where the notion of self-determination comes into play.  Our actions determine the “shape” of our souls and only certain shapes can hold the life of God in them.  Once the soul becomes warped from certain types of actions, then the life of God spills out them.

At this point, one might be willing to concede all that has been said.  But how is it that a single mortal sin could so damage the human will as to make the person unfit for Heaven?  After all, we have been speaking of habits and one slip does not break a habit.  Perhaps this is best answered by way of analogy.  Suppose a man loves his country and strives to be patriotic.  He may have dedicated his life to serving out of love for his country.  This love certainly may not be perfect.  He may love her imperfectly by doing something like not obeying all the traffic laws.  While he would still be viewed as a patriot, he would not yet be a perfect patriot since the love of self that causes him to disobey the traffic laws impedes him from loving his country perfectly.  But are there certain actions in which he would cease to be a patriot?  Would a man who sold secrets to his country’s enemy still be a patriot even if he only did it once?  Everyone recognizes that a single traitorous action would undue all of his previous patriotic actions and he would no longer be considered a patriot.

So too it is with our moral lives.  We may love God imperfectly and commit venial sins, but there are certain actions which we can perform which are so contrary to the love of God that they deform our wills such that the life of God can no longer reside in us.  Just like the false patriot in our analogy, we still have the opportunity make amends for our transgression and have grace restored to us, but at a certain point that no longer becomes an option.  Benedict Arnold can no longer make amends for his act of treason, despite all of his previous acts of patriotism to the contrary.

This brings us to a second important point and that is that at the moment of death our souls become fixed.  We now enter into the realm of spirits and our manner of judging is immutable.  This is one of the ways we become “like the angels.”  Angels, because they are pure spirits, do not change their minds.  Because they can see all particulars attached to their decisions, their wills remain fixed once they have made a judgment.  So too we will do at the moment of death.  Because the soul is fixed in either good or evil by its last voluntary act, it continues to judge according to its inclination at the time of separation.  The will can only change when the judgment of the intellect gives new reasons.  This is why there is only one personal judgment at the time of death—the decision to choose for or against God has been made and cannot change.  This is also why the Fathers of the Church speak of the terrible temptations of the demons at the hour of death as they tempt us towards a mortal sin or away from repentance.  It is also why we pray regularly to St. Joseph, the Terror of Demons, for a happy death.

While we can see how reasonable this teaching is, it remains just informative unless it causes us to measure our actions more carefully.  If it is true that one mortal sin can cause us to lose Heaven then we must actively strive to grow in sanctifying grace.  The deeper the penetration of God’s life into our souls, the greater our protection against sin.  We truly become more and more like God, and it is only those who are truly like Him that can share His life in eternity.  Each day we do not grow in the love of God is a loss.

In closing, we may turn to Blessed Columba Marmion who seems to summarize our approach best:

We shall enjoy God according to the same measure of grace to which we have attained at the moment of our going out of the world. Do not let us lose sight of this truth: the degree of our eternal beatitude is, and will remain, fixed forever by the degree of charity we have attained, by the grace of Christ, when God shall call us to Himself. Each moment of our life is then infinitely precious, for it suffices to advance us a degree in the love of God, to raise us higher in the beatitude of eternal life. And let us not say that one degree more or less is a small matter. How can anything be a small matter when it concerns God, and the endless life and beatitude of which He is the source? If, according to the parable spoken by our Lord in person, we have received five talents, it was not that we might bury them, but that we might make them bear increase.  And if God measures the reward according to the efforts we have made to live by His grace and increase it in us, do not think it matters little what kind of a harvest we bring to our Father in Heaven.  Jesus Himself has told us that His heavenly Father is glorified in seeing us abound, by His grace, in fruits of holiness, which will be fruits of beatitude in Heaven. In hoc clarificatus est Pater meus ut fructum plurimum afferatis  . . . Can it be that our love for Jesus Christ is so weak that we account it a small thing to be a more or less resplendent member of His Mystical Body in the heavenly Jerusalem?