It is mentioned that Abel's father is a politican on earth and that his father wanted him to follow his footsteps and become an politican as well but Abel refused and became a navigator instead.  His father didn't approve of him being a navigator, nor of him joining the alliance, and said that "dying in a territory war is for lowlife colonists". Also, it is said that Abel was the best in his class. 
Life as a navigator
He is teamed up with Cain, the best fighter in the alliance. The two start a relationship.
HamletMachine has said that a potential hobby for Abel would be playing the piano. It has also been suggested that perhaps he was made to take violin lessons as a child.
Abel has black-colored eyes. He is the only named navigator with dark eyes.
According to HamletMachine, "Abel's eye color isn't part of his special ability, he just wasn't as [genetically] modified."