"Whatsoever you do to the least of my brethren, you do also to me," says our Lord in Matthew 25:40.
There is an old saying that we see what is in the heart of a man by how he treats one who can do nothing for him. The same can be said of the faith of a man. Yet, so many people's hearts grow cold and deform into hardening to the point of having malice, which is even one of the 7 Deadly Sins, because they justify their hatred by their false 'faith'. Hatred of sin is not hatred of the sinner, but yet, people will grow so much in their pride, that they will perversely look for reasons and excuses to hate others. St. Mary Magdalene did not have a hatred of the simple man, but impatience can lead to this, and definitely, detesting the Cross will lead to it.
Our Lord appeared as a gardener to Mary Magdalene. Here is was trying to give her an opportunity for her strength to be built up, at the same time, he was teaching her a lesson. She was seeking him, and he did not rise again to be here forever, therefore, he came in the guise for which she would not immediately recognize him. This way, she would learn she would seek him in her heart in not only her prayer, but in all her interactions. It was a humiliation for her, for which she would later learn upon him revealing himself. (She would, then, later seek him in her interior life thereafter the Ascension.) While she was not dismissive to the gardener, she was impatient with him that she sought our Lord. Mary Magdalene came from a class that was higher than a mere gardener, but she sought our Lord, and yet, did not have the faith to 'see' him.
Why does this happen? It happens because at some point, they lose so much charity, because they did not firstly guard their faith. It takes more than just going to Mass on Sundays and Holy Days, but it takes daily prayer, frequent confessions, daily examination of conscience, and a sincere effort daily to live according to the love of God and the love of man out of the love of God --- (in) the fulfillment of the 10 Commandments. People forget these because they become spiritually slothful, and want to throw off the cross. They want a faux "Christ" that did not suffer and die on the Cross. They want to believe that they have "arrived" in sanctity, and that they are definitely on their way to Heaven. Hope is one thing, but presumption is NOT hope. Presumption is sin and a lack of gratitude and contrition for past sins, and amendment for any attachments to sin (whether mortal, or venial, or even imperfections in proclivity to unintentional venial sins due to imperfections).
God did not make it impossible for us to become perfect. Once we believe that it is not possible, we deny the fruits of Christ Death and Resurrection, and in doing so, worship a false "christ". It is not only possible through his graces won for us by opening the doors of Heaven by his death on the Cross, but it is necessary for us to get to Heaven, and more importantly: because Christ commanded us towards this end. We must, therefore, seek to perfect ourselves in sanctity, and not think that this is not realistic or impossible. It is possible, and that is why we worship Christ at Mass; that when we hear, "Ite Missa est!" we take that mission literally, to go and live as God orders us to live.