Why are divorced and remarried people denied the Sacrament, while people who had sex before marriage are not denied the forgiveness and the Sacrament?

QUESTION: I would like to know your opinion on the statements of some hierarchs who propose, in a spirit of mercy, admitting divorced second-weds to Communion, repenting for a broken marriage and striving to live in a Christian way in a new marriage. Indeed, why are divorced, remarried people denied Communion, while young people who have an intimate relationship before marriage are not denied forgiveness and Communion? After all, in fact, both those and others violate the commandment?

ANSWER: the author of the question correctly noticed the obvious thing: both those and others violate the commandment. And he is also right in the first part of his question: divorced second wives are invited (and not only by some hierarchs, but by the traditional teaching of the Church) to go through the path of repentance and to partake of the Holy Mysteries again. But what does this path of repentance mean?