Is it obligatory for Muslims now to follow the Quran and the commands of Allah, and what is the evidence that the religion of Islam extends until the Day of Judgment, knowing that those addressed in the Quran were only the Messenger and his Companions?

The problem is built upon the mistaken belief that the Qur'an and God's commands were revealed only to the Messenger and his Companions. The truth is that Allah revealed the Qur'an as a guide for all beings, humans and jinn alike. It is a reminder for all worlds and a warning to them, not limited to a specific generation. Rather, whoever has received the Qur'an has had the proof established against them until the Day of Judgment. Muhammad (peace be upon him) is the Seal of the Prophets, and all people, from the day of his prophethood until the Day of Judgment, are obligated to believe in him and follow him. Allah has praised those who follow the Companions with excellence until the Day of Resurrection, and He mentioned that those who come after the Muhajirun and Ansar until the Day of Judgment pray for forgiveness for them and for those who preceded them in faith.