In the modern age of the church, I'm afraid we have become far too comfortable with certain words. This has caused them to lose their true meaning. The word "church" itself could arguably be categorized this way. But right now the word I want to address is "ministry".
In today's church, ministry is generally some kind of activity that you help perform. The music ministry, the children's ministry, the women's ministry, the communion ministry, the greeting ministry, etc. And while these can all definitely be considered ministries, we need to understand what the word ministry means. Ministry is literally "service, ministering, esp. of those who execute the commands of others." As Christians we execute the commands of God.
Paul makes it clear, a Christian's first ministry is doing everything we can to execute the command of "be reconciled to God". So, whether it's children's, music, or any other kind of ministry, the real question to ask is - Is this ministry truly executing the commands of God?