Below is a suggestion that may help you to explain to others and especially your children why it is ok to enjoy being a Christian Martial Artist that includes weapons in their fitness curriculum. 

Describe the Church's specific warrior saints. There are many Warrior Saints that carried swords and spears and defeated evil such as St. George and St. Constantine. They stood up for the weak and for the Gospel. They used their shields and weapons prayerfully. Prior to the confrontation they would call upon the Lord to Bless their defense against evil. They used their free will to choose to only use the weapon to defend and uphold the Gospel. These specific Saints upheld the commandments, and did not to seek vengeance, unjust murder, or conscious harm of others. 

A Christian Martial Artist gives God all the Glory while they train and if a self-defense situation arises they train to stay prayerful avoid violence and bring peace to the situation. They strive to simplify body movements to get the maximum results out of their movements with the least amount of energy spent. They strive to watch what they eat so they have the right food in their body to do their training. And most importantly they strive to uphold God's commandments that are the school codes that include treating others the way you want to be treated.

In Addition, a Christian Martial Artist may enjoy using weapons. Weapons themselves have no mercy or malicious intent.  It is the individual that wields the weapon that uses it for good or evil with their free will.

I myself enjoy using weapons for the fitness aspect. I love the added weight to my exercise and enhancement of my body mechanics and hand-eye coordination. I also find it prayerful to strive to use the weapons in the correct way and with the correct angle/direction of use, balance, and removal of evil intent for the weapon is an extension of myself.   

A great passage to read prior to your  Christian Martial Arts weapon training is Ephesians 6:10-18. In this passage you can read about Spiritual readiness. Here are some bullet points from the passage on taking up the whole armor of God.

• Gird your waist in truth, having put on the breastplate of righteousness

• Shod your feet with the preparation of the Gospel of Peace

• Take the Shield of Faith

• Take the Helmet of Salvation

• Take the Sword of the Spirit, which is the word of God

For more information a book I highly recommend sharing with your children is My Warrior Saints by Dionysious & Egle-Ekaterine Potamitis. This book helps children to see the proper use of weapons by many of the amazing Saints of the Church. I always teach safety first and the respect of life that was created by God.