Why does Islam promise in the afterlife that which is forbidden in this world, such as a man's relationship with women outside of marriage, by rewarding it in Paradise with the likes of the Houris?

Allah described Paradise and what it contains in the Noble Qur’an, and He mentioned the women of Paradise (Al-Hur al-’In) in verses and prophetic traditions that describe their beauty and that they are prepared for the righteous. Islam forbids certain things in this world, and rewards those who abandon them in the Hereafter with things that resemble them in name but differ in reality and nature. Allah is the Creator, and He has the right to forbid and permit. It is not necessary to know all the reasons for prohibitions, but some are apparent, such as preserving lineage in the prohibition of fornication, unlike the Houris who are confined to their husbands. The rulings of this world differ from the rulings of the Hereafter; the wine in Paradise does not intoxicate, and the women of Paradise are pure, they do not die or grow old. The prohibition of some matters in this world is a test for the servants.