so...today is the first day of Lent. Observing Lent wasn't on my radar at all this year, but I have observed it in the past.

First...what is Lent?

From Michael Horton at White Horse Inn:

I believe an evangelical celebration of Lent affords an opportunity to reinforce rather than undermine the significance of Christ’s person and work.

Lent is a 40-day preparation for the observance of Christ’s passion and Easter. It gives us an annual opportunity to trace the history of redemption. We learn that the number 40 is associated with a trial, a preparation, even an ordeal that leads either to blessing or curse in the stories of Noah, Moses, and Jonah. Recapitulating Adam’s trial and Israel’s 40 years of testing, Jesus was taken by the Spirit into the wilderness for 40 days, fasting instead of following Adam and the wilderness generation of Israelites in demanding the food they craved (Matt. 4:1-4). Resisting Satan’s temptation with God’s Word, Jesus was the Last Adam and Faithful Israel who fulfilled the trial not only for himself but also for us, as well as bearing the curse for our covenant-breaking.

Reformed folks take both sides of this. Not "you must or you must not: - but rather, "this is a matter of Christian liberty vs. no, it's not"

But...why do Lent?

I think that some observe Lent because their walk is lacking in other ways. When I was in a church that left me feeling dry and foundering, I observed Lent. I spent forty days focusing my devotional time on the coming Good Friday and Resurrection Day - it was time well spent. It took my eye off of what I was not getting in church, and what I already had In Christ.

Tim Challies has about the best take:

To those who plan to observe Lent, I wish you well and trust you’ll benefit from a time you’ve chosen to make special between you and the Lord. To those who plan not to observe Lent, I wish you well also and trust you’ll benefit equally from the so-ordinary, so-wonderful means of grace that are available to all of us all the time.