Making others happy is not a question of sacrificing our own happiness. Trying to make others happy, even when we do not always succeed, is a source of great satisfaction. Anger and hatred are signs of weakness, while compassion is a sure sign of strength.
Cultivating a close, warm-hearted feeling for others automatically puts the mind at ease. It helps remove whatever fears or insecurities we may have and gives us the strength to cope with any obstacles we encounter. It is the ultimate source of success in life.
Peace has a great deal to do with warm-heartedness and respect for the lives of others, avoiding doing them harm and regarding their lives as being as precious as our own. If, on that basis, we can also be of help to others, so much the better.