In his weekly catechesis, Pope Francis used the example of St. Paul and his apostolic zeal. He said it is like the "shoes" of an apostle because they need it to move.
Summary of the catechesis
Dear brothers and sisters:
In our continuing catechesis on apostolic zeal, we have been reflecting on the example of the Apostle Paul. From his earlier experience as a persecutor of the Church, Paul was well aware of the danger of misguided zeal, or a zeal motivated not by love of Christ but by vanity or self-assertion. Authentic zeal for the Gospel is instead, Paul teaches, completely centered on Christ and the power of his resurrection. In his Letters, Paul uses the imagery of putting on the “armour of God” and exhorts his listeners to have their “feet shod” in readiness to proclaim the Gospel of peace (cf. Eph 6:13).
The image is eloquent, since the feet of an evangelist must be solidly planted yet constantly in movement, ever ready to confront new situations in the effort to proclaim the Good News with creativity and conviction. May each of us, in the circumstances of our daily lives, prove zealous in discerning when and how best to proclaim the risen Jesus and his promise of the fullness of life and peace.