"In the second place, many people are deterred from seriously attempting Christian chastity because they think (before trying) that it is impossible.  But when a thing has to be attempted, one must never think about possibility or impossibility.  Faced with an optional question in an examination paper, one considers whether one can do it or not: faced with a compulsory question, one must do the best one can.  You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone.  Not only in examinations but in war, in mountain climbing, in learning to skate, or swim, or ride a bicycle, even in fastening a stiff collar with cold fingers, people quite often do what seemed impossible before they did it.  It is wonderful what you can do when you have to."  Mere Christianity

There are two important things to note regarding what Lewis says in this passage.  First of all, what does Lewis mean by chastity?  He means quite simply that if one is single one must not engage in any sexual activity whatsoever.  This extends to the thought life as well--and there is the real rub for many of us.  But chastity also applies to marriage.  If one is married then one must be completely faithful to one's spouse, sharing the sexual experience only with him or her.

Secondly, it should be noted that with regard to this bit of doctrine Lewis, once again, was preaching from his own experience.  From the time he became an atheist in his early teens until the time he became a theist in his early thirties Lewis did not live a chaste life.  Then, around 1929, he began to make an attempt at complete virtue.  This attempt revealed to Lewis what little he was able to accomplish by his own power as he continually failed in regard to chastity, and then made renewed attempts at obedience.  This experiment also led him to rely more on God and seek the power of the Spirit.  Once Lewis became a Christian in 1931 he found a new power through Christ to overcome temptation in the area of his sexuality and the Lord enabled him to live a chaste life in singleness and eventually a faithful life in his brief marriage to Joy Davidman Gresham.

As Lewis notes elsewhere, only Jesus knows the full power of temptation because only Jesus fully resisted temptation at every point.  This same Jesus can give us power to resist temptation, not only in the area of sexual morality, but in every department of life.  Jesus can reveal to those who seek it the glory and the joy of a chaste, pure, holy life--the only life really worth living.

Jesus said, ". . . apart from me you can do nothing" (John 15:5).

The Apostle Paul wrote, "No temptation has seized you except what is common to man.  And God is faithful; he will not let you be tempted beyond what you can bear.  But when you are tempted, he will also provide a way out so that you can stand up under it" (1 Corinthians 10:13).

And Hebrews 4:15-16 tells us, ". . . we do not have a high priest who is unable to sympathize with our weaknesses, but we have one who has been tempted in every way, just as we are--yet was without sin.  Let us then approach the throne of grace with confidence, so that we may receive mercy and find grace to help us in our time of need."

Dear Father, help me by your Holy Spirit to live the chaste life you created and redeemed me to live by your son Jesus Christ.  Thank you Lord Jesus for living a completely chaste life for me.  Thank you for dying on the cross for my unchastity.  Thank you for rising from the dead that I might receive new life and new power to live in your holiness.  Amen.