What is love?

Love is choosing to do what is best for another person. Love is an action, not a feeling. (Though feelings are often a byproduct. Why do we feel so great when we are dating? Because we are making every effort to do nice things for the other person. We choose to treat the other person well.) We are acting in a way that shows love.

So love is helping others, meeting their needs, putting their well being first. If you love some one you will not cheat on them, lie to them, steal from them, etc. God introduced his laws about love 3500 years ago through Moses. You may be familiar with his Top Ten.

For he who loves his fellowman has fulfilled Gods law. The commandments, "Do not commit adultery," "Do not murder," "Do not steal," "Do not covet,"and whatever other commandment there may be, are summed up in this one rule: "Love your neighbor as yourself." Love does no harm to its neighbor. Therefore love is the fulfillment of the law.
Romans 13:8-10

The opposite is selfishness. Wars are fought because people want the land that belongs to others. People murder and rape others because they want to take something from others or get back at someone for hurting them. Entire countries suffer famine and starvation because dictators oppress people. People steal from others because it is easier than working hard to earn money to buy things. Men use women for sexual pleasure in short term relationships rather than making a life long commitment to build a life and family together. People lie to cover up their selfish behavior rather than facing the consequences of how their actions have hurt others. Many seek escape from the painful aspects of life in alcohol, drugs, and entertainment rather than taking responsibility to work hard at changing those things. And there are many other subtler forms of selfishness, like simply not doing anything to help others when you could.

All these things cause pain, suffering, death, and hurt. It is people choosing to love themselves, not love others, that makes this world a miserable place. But God has a solution.