In the Vachanamrut of Gadhpur Pratham 1, Lord Shree Swaminarayan explains that if one is always conscious of the Lord (Akhand Vrutti), then there is nothing left for that person to do.
Chanting the divine names of the Lord is important in one’s endeavour of devotional service unto Him, thus the ‘Mahamantra’ i.e. ‘Maha’ meaning ‘great’ and ‘Mantra’ meaning ‘magical spiritual formula’. Mahamantra is also a sacred name that qualifies the cherished Deity and their worship. To attain that engagement with the Lord as described in the Vachanamrut above, chanting is the master key to unlock the locked doors of life.The divinity experienced through chanting liberates the mind from the mode of ignorance and elevates it above the three-fold modes (Satva-Rajas-Tamas)
Krute yad-dhyaayato Vishnum, Tretaayaam yajaato makhaih, Dvaapare paricharyaayaam, Kalu tadd-Hari-kirtanaat
Shreemad Bhagwatam Canto 12, Chapter 3 & Shreemad Satsangi Jeevan Canto 4, Chapter 34
In the verse above, Lord Ved Vyas states that ‘Just as one attains merit through the mediation of God in Satyug, offering sacrifices to the Lord through the holy fire in Tretayug, worshipping the Lord with various offerings (with shodasopacara, the sixteen kinds of paraphernalia) in Dvaaparyug, one attains all the merits of these combined through chanting the names of the Lord in Kaliyug.’ Lord Shree Swaminarayan also states the very same in the 4th canto, 34th chapter of Shreemad Satsangi Jeevan.
Naama sankirtanaam yasya, sarva-paapa pranaasanam, pranamo dukha-samanas tam namaami Harim param
Ved Vyas, Shreemad Bhagwatam Canto 12, Chapter 13
In the conclusion of the 12th canto of Shreemad Bhagwatam, Lord Ved Vyas states ‘I offer my respectful obeisance unto the Supreme Lord whose congregational chanting of holy names destroys all sinful reactions and who relieves all material suffering.’
So what is the connection between chanting the Mahamantra and writing/typing the Mahamantra (Mantralekhan)?
The aim of chanting the Mahamantra is to remain conscious of the Lord (Akhand Vrutti); Mantralekhan has the same result as we would naturally be inclined to chant while we type, thus fulfilling the aim of being conscious of the Lord.