Pre-Revolution Russia, many people Russian people talk about having a picture of the Czar right next to a cross. Peasants seemed to truly see the Czar as the closest person to God. How did a political title get such a religious heir to it? Did a Czar at one point go out of their way and convince people that he was second to God? Or did the people give the title of Czar that holy heir, and the later Czars just ran with the idea? Did it become an official part of the eastern orthodox religion?
P.S. Is it Czar or Tsar? I always use Czar, but what should I use?
Easy answer first, the term most commonly used within historical scholarship is tsar.
Firstly, before I begin, it's very important to realize that not all Russians are Eastern Orthodox nor were all members of the Eastern Orthodox religion Russians. There were many dissenters and religious minorities within imperial Russia and not all of them placed the tsar as a holy man. Some, such as the Old Believers, saw such a sentiment as heretical.
The tsar was the spiritual head of the Orthodox faith, but he acted less like a Pope or religious figure and was more akin to the English monarch being the head of the Church of England. This assumption of religious authority started in 1721 with the death of the last Patriarch of Moscow. Peter the Great entrusted the control of the church to a newly created administrative unit called the Holy Synod. The tsar appointed the head of the Holy Synod and acted as its protector. Peter's successors would keep the Holy Synod in place all the way up until 1917.
Older scholarship has characterized this relationship as subordinating the interests of religion to the state; thus in effect rendering the Orthodox Church into the handmaiden of the Romanovs. Recent research has made this assertion much harder to accept. In general, the tsars stood aloof from theological issues and the close supervision by the state produced a more educated clergy.
Within the Russian empire, Orthodoxy became a convenient short-hand for the state to discern which of its vast and diverse populations were loyal and which needed to be closely supervised. Starting in the nineteenth century, the tsars increasingly reemphasized their role as the head of the faith. This reached its apogee with the conservative tsar Alexander III whose imperial style of rule emphasized Russian orthodoxy in a manner that previous tsars did not.
As to the question of did the peasants see the tsar as a holy man, the answer is much harder to parse out. While there are many instances of the kind tsar in Russian folklore, the religious attitudes of the peasantry are notoriously difficult to pin down. However, most evidence would indicate that the tsarist pretenses towards holiness grew harder to maintain during the nineteenth and twentieth centuries. After 1905 allowed a degree of religious freedom (legally, all subjects of the tsar had to declare a religion and once one "converted" to Orthodoxy, they could not revert back) a number of peasants applied to convert back to their original religions. Some Orthodox reformers like Father Gapon tried to urge the tsar to act as a christian, but the fusing of religious and secular authority often means that one has to suffer in times of crisis. By 1917, contrary to popular expectations, the Romanovs enjoyed relatively little popularity in the Russian heartland and much of the blame for the war's misfortunes.
Sources
Chulos, Chris J. Converging worlds: religion and community in peasant Russia, 1861-1917. Northern Illinois University Press, 2003.
Freeze, Gregory L. "Handmaiden of the State? The Church in Imperial Russia Reconsidered." The Journal of Ecclesiastical History 36, no. 01 (1985): 82-102.
Kivelson, Valerie A. Orthodox Russia: belief and practice under the tsars. Penn State Press, 2003.