Do not let yourselves be easily moved from your way of thinking, or be disturbed (alter or disturb), neither by spirit, nor by word, nor by letter ... A firm tree is one that has deep roots, a firm building is one that has strong and deep foundations. The firmness has everything to do with the part that we do not see of the great structures and the big trees, this is how it works with our relationship with God, to stand firm in what we believe is not achieved by dressing, behaving or speaking as Christians, but it has everything what to see with the part of you that only you know, has to do with your heart, with the time you invest in knowing God, with the level of integrity with which you behave when no one sees you.