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 fourth and final one is TEACHING.
If we are going to call ourselves disciples, then we must respond to the Great Commission, which calls us to teach new disciples everything that Jesus has commanded us. Discipleship is holding to these teachings. There is a long list of things we could teach each other that would be helpful in our faith, but Jesus has a special way of boiling it all down to the absolute most important teachings. He also makes it clear in Scripture how the world will be able to tell if we are truly His disciples.
Ultimately, everything comes down to obeying Jesus' command to love. This is the greatest command for us to obey. Obedience is expressed through the fruit of the Spirit and leads to freedom.
What is critical to teach children is that being a disciple means obeying and acting like Jesus, especially by loving God and loving others.
The guiding question for a disciple or church could be, Are people being set free and becoming more like Jesus?