Joseph's brothers hated him. This hatred sprang from their envy. Envy usually springs from a lack of self-esteem which brings feelings of sadness, suffering or rejection. Its root is the temptation to comparison. I see the good fortune or the great talents of another and I am sad and hence envious that I do not possess them. Thus Joseph's brothers felt that their father loved Joseph "best of all"; that is to say, they felt Israel loved Joseph more than he loved them. Here is the comparison that generated their envy, their hatred and eventually their murderous scheme.
This feeling blinded them to the fact that their father certainly loved them also just as much but in a different way. The reason for Israel's love for his youngest son is clearly stated: Joseph was "the child of his old age." It was not rooted in any comparison.
Sometimes people feel that God loves others more: others have better health, better fortune, better prospects. When the temptation to think in that way comes, it is best to take to heart the words of Mary's Magnificat: "He who is mighty has done great things for me."
Father in heaven, keep me free from all envy and grant me the grace to acknowledge and praise You as the Lord who has done great things for me.