Man detects two forces in the world: 1) The rejecting force, so one will move from the state he is in. 2) The attracting force, which draws a person, for which reason he must move from the state he is in.
The rejecting force is called “suffering.” The fact that he suffers in the state he is in makes him leave that place and go look for a place where he can enjoy life.
The pulling force is called “pleasure.” If a person sees that there is a place that if he went there he would receive more pleasure than he has in this place, although he has pleasures here, if he sees that he can enjoy life more in another place, he leaves his place and goes there.
However, one force is not enough, since there is a possibility where he will be dissatisfied with the situation he is in, but will not see where he will be better off. Our sages bring an allegory about a pigeon that had a snake under the rock and a hawk up in the sky, so where could it go? While Israel came out of Egypt, the sea was before them and Pharaoh and the Egyptians were behind them.
Sometimes we can receive more pleasure, but we must make an effort. Hence, a person is afraid to leave his place so he will not be left empty handed on either side.
But when there are the rejecting force and the pulling force, a person can move from his place. That is, when one feels suffering where he is, and believes that there is a place to go and receive pleasure, he goes forward. This is called “Turn away from evil and do good.”