You will find much similarity between chapter 12 and Matthew’s Sermon on the Mount, as well as Matthew’s second teaching section in chapter 10. But what you will not find (because Luke is the only one to tell it) is Jesus’ parable in 12:13-21.
The rule of thumb was that in inheritance, the oldest son received a double share. In a family with 2 boys, the oldest son received 2/3 of his father’s estate. This may well have been the problem – the younger son objected. Or, it may have been that one of the boys (even the oldest one) was disinherited and was trying to circumvent the will. Whatever the situation, the end result was animosity between the brothers – all over worldly goods.
Parents do not owe their children an inheritance – and children should remember that. Anything received from a parent is a blessing. Sometimes, parents leave more to a specific child because they believe the child might need it. Sometimes, that child is seen by his siblings as an unworthy heir who is likely to squander such an inheritance – as he has every other gift the parent has given him. But this is the parent’s last gasp to provide for a child they believe is weak. No one has a right to an inheritance in the first place, so properly, no one should complain.
Somtimes, parents deliberately play favorites. It’s hard for the other children to stomach – not because of the amount of inheritance involved, but because it is the parent’s final expression of a child’s value. No parent, dealing with a child in such a manner, can be said to be godly.
Then, there is the category of parent who, though faithful to God and a dedicated servant in His kingdom, forgets God when it comes to the end of life. In some cases, more emotion is expended on how to divide the estate among children who have evidenced no love for God in their adult lives. God has already disinherited them – but the parent never thinks about it. Faith has never really penetrated the deep recesses of the heart.
In the end however, this parable is not about the parent, but about brothers who become divided over material wealth. The focus of life should not be on how much you have here, but how rich your relationship is with the Lord, a richness that is impoverished when people who should love one another fight over money.