The Bible has several scriptures on this; Leviticus 19:18 says, "Do not take revenge or bear a grudge against members of your community, but love your neighbor as yourself...", Deuteronomy 6:5-9 says, "Love the Lord your God with all your heart, with all your soul, and with all your strength. These words that I am giving you today are to be in your heart. Repeat them to your children. Talk about them when you sit in your house and when you walk along the road, when you lie down and when you get up. Bind them as a sign on your hand and let them be a symbol on your forehead. Write them on the doorposts of your house and on your gates." Matthew 5:44 says, "But I tell you, love your enemies and pray for those who persecute you,", and John 13:34 says, "I give you a new command: Love one another. Just as I have loved you, you must also love one another."
The above scriptures tells us how we are to love each other (and be an example for the generations to come) and as I said before it is easier said than done. I believe most of our problem is that we want to 'feel' love but that is not what love is, after all we are all sinners and have more than likely been on the opposite end of being the one who has hurt or wronged someone. We tend to expect others to love us when we do wrong but are we able to do the same? It is a two way street. I for the longest time did this, I expected people to forgive my behavior and forgive and love me but I was not being very loving in return. I would act loving to those that were easy to love but those that drove me nuts or wronged me in my life I was "nice" to but not very loving. I even wished that they would "get what they deserved" which was not extending love, grace or mercy to them.
I have learned through many of these relationships that I needed to extend love, grace, and mercy to them. It has been an amazing experience seeing the change in my relationships as I extended love (even when it is not deserved) without expecting anything in return. Also I have learned that love is not a 'feeling' but an action.
As we live this way people and our younger generation sees this and learns through our example. We as humans will slip up but God offers us love, grace, and mercy which we do not deserve due to our sin nature. So we should extend this to each other being the example loving regardless of what we 'feel' or 'get' in return.