Why make an effort to get saved if my life is pre destined by God?

The Bible does state very many times that God already knows our earthly and eternal destinies. Jesus chose Judas Iscariot because he knew his destiny was to betray him. Jesus knew Paul would try to persecute the church in Damascus and intercepted him on the way. Jesus also knew the thief to his right will confess and they will be re united paradise the same day. My question is, if God already knows who gets to be saved and who doesn't, why should anyone make an effort to be saved when an individual's destiny is already known to God?