The Hated Wife's Firstborn
The Rama reads the two wives of Devarim as two kinds of souls, and finds greater honor in the one who battles.
On the verse about a man with two wives, one loved and one disliked, the Rama sees two types of souls. The loved wife stands for the soul that comes into the world as a tzaddik, free of any pull toward evil. The disliked wife stands for the soul that arrives carrying a yetzer hara, and must fight and endure many trials. The Torah then says the firstborn is the son of the disliked wife, and he receives a double portion. In the Rama's reading, this teaches that one who is born with an inclination to evil and struggles against it stands higher than one who never had to struggle. The effort itself is what earns the greater share.
Source: Meah Kesitah, p. 93, on Devarim 21:15
If something in you pulls hard in the wrong direction, whether anger, laziness, speech or appetite, do not read the pull as proof that you are failing. Today, when it rises, notice it and name it quietly to yourself. Then choose the better action just once, even in something small. According to the Rama, this struggle is exactly where a Jew earns his double portion. And when you see another person fighting a difficult battle, remember that they may be standing higher than you know.