That's why God never asked if you wanted to be confirmed. Such a question would be inappropriate. This is not for you to decide. You're a sinner after all. You can no more make a lifelong commitment to God than you can make a commitment today to your future wedding plans, what kind of a career you will choose, or what kind of a grandparent you will be. It's all by God's grace and mercy that you are confirmed in baptism and brought here today to confess before witnesses that, yes, for Christ's sake, God is good to you, keeps his promise to be your God, and holds you in his grace and mercy all the days of your life.
The Warrior Priest Podcast