What is the ruling on Hajj, and what is the ruling on one who denies its obligatoriness?

Hajj is one of the pillars of Islam. Whoever denies it or despises it after being informed is an apostate who should be asked to repent. If he repents, well and good; otherwise, he should be executed. The able-bodied must hasten to perform the obligatory Hajj, for Allah Almighty says: ﴿And Hajj (pilgrimage to Makkah) to the House (Ka‘bah) is a duty that mankind owes to Allah, those who can afford the expenses (for one’s conveyance, provision and residence); and whoever disbelieves [i.e. denies Hajj (pilgrimage to Makkah) is a duty that mankind owes to Allah, and does not perform it] then Allah stands not in need of any of the ‘Alamin (mankind and jinn).﴾