Basically, I contend that there are many things you could not do and still be a Christian, or follower of Jesus. For example, you could not "go to church" or participate in a youth group or listen to Christian radio stations or become a missionary in a foreign land or tithe or...okay, you get it...and yet still be an authentic, sincere, passionate follower of Jesus. These examples may all be good things, but they are not the marks of true discipleship that Jesus gives us in the Bible. They are not the "make-or-break", non-negotiables of the Christian faith used to identify people as real believers.
Then, what are the non-negotiables?
The second one is GOING.
The idea here is to do good everywhere God sends us, individually and corporately. Although it's a little cliche, I like to say that our mandate is to choose what is right, and change what isn't.
The Great Commission tells all disciples to go and make disciples. Our identity in Christ is as a "sent" people. We are described in the Bible as ambassadors, reconcilers, and apostles.
The key is to see this practice as service in our everyday, real life contexts. We find ourselves in the mission field in our normal, daily lives in the marketplace, work, and home. This is one of the reasons the term "organic church" is used, because God plants us in all kinds of soil and we can organically respond to our natural surroundings.
What is important to stress to children is that Jesus taught us to worship God by doing good everywhere we go. It is how we praise Him.
The guiding question for a disciple or church could be, Are we doing good works that help people and glorify God?