There is a saying : "United we stand, devided we fall". A single hand has a limited capacity, but more hands working together will have much more strength to apply on a particular thing at the same time. So we should be united in all our missions of life. A single person's family is somewhat weak in the sense that there is hardly any other person to hand by his side in his calamity. But in a joint family, there are other members of family who can come forward to one another's rescue in the days of calamity. In case of our country also, the same example is applicable very appropriately. When the native Land is attacked by any outside enemy, it's not a single or a few people's job to fight the enemy. It's the collective force of all the countrymen to fight out the evil. Thus unity is always proved to be a great source of strength. It is really like an invincible constructive or destructive performance.