Lent is a spiritual battle, whether we realize it or not. It is a time when we imitate Jesus' 40 days of temptation in the desert.
Pope Benedict XVI pointed out this aspect of Lent in a homily he gave on Ash Wednesday in 2006:
Another aspect of Lenten spirituality is what we could describe as "combative", as emerges in today's "Collect", where the "weapons" of penance and the "battle" against evil are mentioned.
Every day, but particularly in Lent, Christians must face a struggle, like the one that Christ underwent in the desert of Judea, where for 40 days he was tempted by the devil, and then in Gethsemane, when he rejected the most severe temptation, accepting the Father's will to the very end.
For us, "It is a spiritual battle waged against sin and finally, against Satan. It is a struggle that involves the whole of the person and demands attentive and constant watchfulness."
It is the perfect time to examine our own lives and see which sins we hold onto, whether they are big or small.
Pope Benedict XVI explains that sometimes the "little sins" we commit deserve an equal amount of effort to eradicate:
St Augustine remarks that those who want to walk in the love of God and in his mercy cannot be content with ridding themselves of grave and mortal sins, but "should do the truth, also recognizing sins that are considered less grave..., and come to the light by doing worthy actions. Even less grave sins, if they are ignored, proliferate and produce death" (In Io. evang. 12, 13, 35).
So while we should try to eliminate our more serious sins, we shouldn't neglect the little ones that can sow the seeds of death in our spiritual lives.
If we ignore the "little sins" in our lives, they can become the big ones that lead us away from God.