If you found out that the elections depended upon you and you alone – would you go out to vote?
Would you offer to take your friends with you? Would you go around to where a little old lady lives and drive her to the polling station in your car – maybe picking up on or two of her friends on the way?
You should, because it is a numbers game. There have been elections won by tiny margins. Later is no time to be sorry when the party that you intensely dislike has come in and changed the way that Israel is today and will be in the future.
In some countries voting is compulsory with people being fined if they do not vote. In Israel voting is optional and this is to the disadvantage of many sectors of the population who only find out later that their vote could have had an impact on the results. Traditionally people who do not vote come from the lower socio-economic classes, illiterate people, older people who do not have easy access to transport, busy mothers of large families, uneducated people and those who simply do not care or who despise politics - and also those who 
You may be fired up to vote for one of the parties that will not cross the threshold because you totally agree with their principles. If they are projected not to get into the Knesset your vote will go nowhere. It would be better to vote for your second choice.
have plans for the election day vacation and can't be bothered.. Understand that when you do not vote the winners will be the party determined by ones who do go out to vote.
Not only can you make or break the winner in the coming election, your family and friends are part of your influence circle. If your son or daughter does not believe that it is important to vote and finds something else to do on voting day it is your responsibility to discuss this well in advance. If they have no idea who to vote for you can sit down with them and explain the parties, their agenda, their personalities and their past statements and actions. They also may have been influenced by friends or the media. If you have something to contribute to their point of view do so. They may not have considered what you have to say.
You can also waste your vote. You may be fired up to vote for one of the parties that will not cross the threshold because you totally agree with their principles. If they are projected not to get into the Knesset your vote will go nowhere. It would be better to vote for your second choice.
One last contribution that you can do. Your chosen party in your city has volunteers who drive people who are unable to get to the polling station to vote, and others who assist those who are illiterate. Join your group and make a big difference to those who otherwise would not be able to participate in the election
Your vote and your time are both valuable.