What about using deen as income?

In Quran (12:104) it is written:

‘And no reward you ask of them for it, it (the Message) is no less than a Reminder and an advice unto the ‘Alamin (men and jinns)’

Also see 6:90 , 10:72 , 11:51, 25:57, 26:109, 26:127, 26:145, 26:164, 26:180, 34:47, 36:21, 38:86, 42:23 and 76:9.

Uthman bin Abi Al-As narrated that the Messenger of Allah (SAW) made him the Imam of my people and said,

“You are their Imam, so consider the weakest among them and choose a Mu’adhdhin who does not accept any payment for his Adhan.”

Sunan Abi Dawud 531 (http://sunnah.com/abudawud/2/141), Sunan an-Nasa’i Vol. 1, Book 7, Hadith 673 (http://sunnah.com/urn/1006770)

It was narrated that ‘Ubadah Ibn Samit (RA) said:

“I taught people from Ahtus-Suffah” Qur’an and how to write, and one of them gave me a bow. I said: ‘It is not money, and I can shoot (with it) for the sake of Allah., I asked the Messenger of Allah (ﷺ) about it and he said: ‘If it would please you to have a necklace of fire placed around your neck, then accept it.'”

Sunan Ibn Majah Vol. 3, Book 12, Hadith 2157 (http://sunnah.com/urn/1264760)

Abdur-Rahman ibn Shibl (may Allah be pleased with him) reported that the Prophet (peace be upon him) said,

“Recite the Quran; act according to it; do not abandon it; do not be excessive regarding it; do not earn livelihood by means of it; and do not seek increase (in wealth) through it. ”

[Reported by Ahmad, At-Tabarani and Al-Bayhaqi]

`Umran ibn Husayn (may Allah be pleased with him) reported that the Messenger of Allah (peace be upon him) said,

“Recite the Qur’an and ask (the favor of) Allah by it before the coming of some people who recite the Qur’an to ask (the favor of) people by it. “

[Reported by Ahmad, At-Tabarani and Al-Bayhaqi]

Further in a hadith, Allahu ta’ala taught Hadrat Adam (AS) a thousand arts and craftworks and ordered him:

‘Let your children seek their sustenance through one of these arts and craftworks. Let them not make the religion a means for earning their livelihood.‘ [Hakim]

The stronger a person’s connection with his Lord becomes, the more he will feel relaxed. This is why they said to Ibn al-Mubarak: “Who are the kings?” So, he replied: “Those who abstain from the worldly pleasures.” They asked him: “Who are the lowest of people?” He replied: “Those who eat with their religion,” meaning they are hypocritical with the people. So, they do this for a bite of food or a badge of honor, or any other worldly gain. They asked him: “Who are the lowest of the low?” He replied: “Those who ruin their religion in order to gain wordly benefit for others.”

As per some people if Imam/scholar doesn’t want to get too distracted by other things (trade etc.) there is no other way than to fix some allowance for them to focus their time in religious things, which otherwise is the duty of all types of people (http://islamqa.info/en/146964, http://islamqa.info/en/120)