Mecca and Madinah are cities of great importance in Islamic tradition -- centers of pilgrimage and prayer, sacred places where Muslims are free from the distractions of daily life.
It is true that only Muslims are allowed in the Sacred Mosque in Mecca. The simple reason it is so, is because it is the command God Almighty made in the Holy Quran.
Allah says in the Holy Quran Chapter 9 Surah Taubah verse 28:O you who have believed, the ‘mushriks’ (polytheists) are ‘unclean’; therefore, let them not come near the Sacred Mosque (of Mecca) after this year.
The ‘unclean’ is used in the verse in the spiritual sense, not the physical sense. Allah has commanded that no polytheists must be allowed to enter the Sacred Mosque, and this command will stand till the end of time. Therefore, there is no one who can facilitate your visit to the Sacred Mosque, except yourself. If and when you testify that there is no god but God Alone, and that Mohamed is God’s slave-servant and Messenger, you are more than welcome to visit the Sacred Mosque.
There are millions of mosques around the world, and if you wish, you are more than welcome to visit any one of them. This command is specifically only for the Sacred Mosque in Mecca.