What is the ruling on premarital relationships, and what are their effects on a person's future after marriage?

Establishing relationships between young men and women before marriage is one of Satan's steps that lead to what is forbidden, and it has negative effects on the present and the future, as stated in the prophetic hadiths that warn against the temptation of women. These relationships have caused the violation of honor, deprived girls of marriage, led to abortions, and even infanticide, and the deviation of young people. These effects may, in most cases, lead to a deviant marital life. Nevertheless, conditions may improve by the grace and generosity of Allah, for sincere repentance expiates sins and may rectify a person's situation after repentance.