In the First Reading, Moses challenges the people, and us, to "choose life". He says, "choose life, that you and your descendants may live." This seems pretty practical. If we choose life, we and our descendants will go on. If not, well...
However, I think we need to look deeper. In fact, I would encourage you to insert a word here in the scriptures, if only mentally - "choose eternal life." For most of us, choosing life is not much of a choice in the arena of our daily lives. Most of us do not rise in the morning with the thought of I'm going to choose to live this day racing through our brains. Yet choosing eternal life must be an everyday, and in fact every moment, choice. It is an effort to make those choices day after day and minute after minute. In some degree, every choice we make throughout our day is a choice for either eternal life or eternal death - therefore choose life!
So how then do we "choose life"? The Gospel gives us the answer. We choose the Cross. This is certainly a paradox but it is the instruction of Our Lord. In fact, He gives us a frightening teaching concerning the choice for the cross later in Luke 14:27, "Whoever does not bear his own cross and come after me, cannot be my disciple." Our Lord says, "cannot" and that is not to be taken lightly.
In choosing the Cross, we choose life, eternal life. Taking up our Cross daily is not an option, it is a requirement. Those who seek to "save their life" by fleeing the Cross will lose it, for in reality they are choosing death, eternal death. They are, in fact, choosing to flee from a holiness and joy that can only come from God Himself - the student is not greater than the master.
Lent gives us plenty of opportunities to once again choose the Cross, to choose life. We are invited to take upon ourselves little crosses. We are encouraged to give up something we are fond of and make sacrifices by doing that which we don't really like. My giving up coffee or meat is supposed to be removing something from my life in order to make more room for God. Most often the "room" or space that is made is in the shape of a Cross.
If I think fondly of and desire my coffee, I should take the time to think this way, "I could have that coffee right now and be satisfied...for a while, but I would only want more. I now make the choice to desire Christ who will satisfy me for eternity. I accept this cross and in doing so, I choose life, eternal life." The hunger of fasting should make me hungry for God. The desire for that which I have given up should make me desire God. In choosing the cross throughout Lent, I choose life!
"A Christianity from which we tried to remove the cross of voluntary mortification and penance under the pretext that these practices are the remains of the Dark Ages or of an outworn Mediaeval era, quite inappropriate for a modern Humanistic Age, would be an insipid Christianity, a Christianity in name only. It would not have kept intact the doctrine of the Gospels, nor would it serve to induce men to follow in Christ's footsteps." - J. Orlandis, The Eight Beatitudes (Take from In Conversation With God Vol. 2