The 'Humanity March' sought to bring members of different faiths, ethnicities and cultures from across the country together in favour of peace, pluralism and interfaith harmony.
The statement is the latest sign of ISIS's disregard for cultural heritage and its spurious interpretation of Islam.
Religious scholars from Pakistan and abroad denounced terrorism at a conference April 14 in Islamabad. Many say ignorance of Islamic teachings is at the heart of the problem.
Hindu temples and shrines also co-exist with mosques throughout the country.
Observers say the festival is a representation of the diverse society that the country's founder, Muhammad Ali Jinnah, had always envisioned.
The joint statement is considered an 'important step forward in the dialogue between Christians and Muslims'.
Al-Qaeda says ISIS members are unable to understand Islamic texts and are bent on carrying out treason and treachery wherever they have influence. The same however could be said of al-Qaeda.
Christmas trees, colourful lights and glittery decorations signal the start of Christmas celebrations.
Khwendo Kor, a non-profit, is working through its growing network to overcome religious intolerance by advancing interfaith relations and societal harmony.
Sikhs have praised the visa-free Kartarpur Corridor, which will link two holy shrines in India and Pakistan.