The Soulborn And You: The Basics
The Soulborn is a Base Class in Magic of Incarnum that is quite similar to a Paladin with Incarnum abilities instead of spellcasting. That said, the Soulborn is pretty bad. It has a paladin chassis, only slightly less restrictive alignments, and very little defense. From here on out, I will stop bashing on this poor, poor, class, and actually help people play one. Hopefully.
Now, let's look at ability scores.
Strength: Hello, melee class anyone? Unlike many melee classes, the Soulborn is less dependent on strength at later levels, as many of your soulmelds can serve to augment your melee capabilities. If you are playing a combat maneuver-focused character, this is very important at low levels, but tapers off sharply in usefulness at later levels with a certain soulmeld that would do you much good to shape.
Dexterity: Eh, it's mostly useless for you, as, like the paladin, you benefit from heavy armor much more than you do from light armor. If you really want to, you can use a ranged weapon, but I would advise against it.
Constitution: You are a meldshaper, primary melee combatant, and fairly competent tank. This is your most important stat.
Intelligence: You are not a skill monkey. It is fairly safe to dump this.
Wisdom: Dump it unless you need it for a PrC of feat. Find some other way to get your will save up.
Charisma: This is a very good ability for you. Your smites are an important part of the class, so any added benifit to your smites are welcome.