Obviously this question could and would be answered differently depending on who is doing the answering, and I even hesitated to attempt an answer because there are so many possibilities (which is a sad statement about the condition of our world). So, take my opinion as just that, please: my opinion.
"In order for humanity to move forward," we must care about the children who are not allowed to grow into adulthood. The reason this seems essential to the demonstration of man's humanity is that children are the most vulnerable citizens on the planet and therefore need--and deserve--the most protection.
The truths and behaviors which must change in order to achieve this goal are many, but here are a few.
First, children in the womb must be universally treated as human beings. This is a controversial position, I know; however, these children have the fewest protections but need them the most in order to have the opportunity just to live. This means changing how the law determines when life begins as well as the laws concerning abortion. Worldwide, the statistics on the number of children who have their laves taken from them is staggering.
Second, children should not die because they do not have enough to eat. In a modern world, it is not a lack of resources or technologies but a lack of will which allows so many people, and particularly children, to die of starvation.
Global hunger now afflicts nearly a billion people worldwide. Severe acute malnutrition, however, is the more immediate killer: it threatens the lives of 19 million children. Every year at least 3.5 million of them die from malnutrition-related causes.
It may be a difficult goal to achieve, but it is certainly not impossible. Food is a basic necessity, and the world's children should not be deprived of it simply because it will cost us something to give it to them. By the way, the same thing should be true of any basic necessity which children deserve to have but do not. This will require little more than a global commitment, for once the commitment is made, people will find the proper resources to get it done.
Finally, the world's children must be protected from harm by adults. While everyone deserves to be protected from harm, children need our help to be protected. Awful things like human trafficking and the sex trade industry (including child pornography) which cater to the debased and depraved who want to abuse children must be stopped. Children in abusive situations must immediately removed, as well, There are hundreds of things like these which prey on innocent children who cannot defend themselves; in every case, the resources to protect them must be a priority and strict laws and punishments must hold all offenders accountable for their actions.
How a society, or a world, treats its children is an indication of how it treats (or will treat) its elderly and its disabled. Our world has moved the markers on this spectrum, it seems to me, and the natural result of mistreating (through negligence as much as through abuse) these groups will be the eventual devaluation of every human being.
We protect what we value, and, judging from the data, we do not value our children. A world which does not take care of its children is a world which has misplaced--or replaced--its values.