Some extracts from The Sayings of the Desert Fathers:
42. Abba Sisoes said, 'Let yourself be despised, cast your own will behind your back, and you will be free from care and at peace.'
7. Abba Anthony said, 'I saw the snares that the enemy spreads out over the world and I said groaning, "What can get through from such snares?" Then I heard a voice saying to me, "Humility."'
2. He (Abba James) warned anyone who receives praise to think of his sins and realize that he does not deserve what has been said of him.
55. He (Abba Poemen) also said, 'As the old men were sitting at a meal one day, Abba Alonius got up to serve and when they saw that, they praised him. But he answered absolutely nothing. So one of them said to him privately, "Why don't you answer the old men who are complimenting you?" Abba Alonius said to him, "If I were to reply to them I should be accepting their praises."'
The Desert Fathers, while not always in agreement, were absolutely unequivocal on the point of pride, even in the tiniest degree. There is no room for pride because Christians endeavor to follow Christ in taking not only our own sins but the sins of mankind on our backs and as our personal responsibility. You can't have a straight back if you're bearing a Cross. Furthermore, the meek and humble are exalted because only they are capable of loving the world. Pride creates envy, and you can't love your neighbor much less your enemy if you're envious of them, nor can you if you are restricted to egotistical self-love.
I would modify Azurestone's post
All sins lead to Pride.
And say that Pride leads to all sins. Pride is the starting point.