A court in Oryol in western Russia sentenced Christensen to six years in a criminal colony, according to TASS. Christensen's lawyer says he will appeal the decision.
Christensen's conviction is part of a campaign against Jehovah's Witnesses and other minority religions, say religious freedom advocates, as Russian Orthodox Christians seek to preserve their cultural dominance.
In 2017, Russia's Supreme Court banned Jehovah's Witnesses as an "extremist organization." According to a spokesman for religion, 1
UN High Commissioner for Human Rights Michelle Bachelet said she is "deeply concerned" by Christensen's conviction.
"The harsh punishment imposed on Christensen creates a dangerous precedent and effectively criminalizes the right to religious freedom or belief in Jehovah's Witnesses in Russia," Bachelet said.
Religious freedom advocates in the United States also expressed concern.
"It is obviously not enough for the state to feel peaceful groups like Jehovah's Witnesses extremist", it must also capture their members.
The Commission last year called for Russia to designated as a "special concern country" under the International Law on Freedom of Religion.The US Department of State has also placed Russia on a watch list to "engage in or tolerate serious violations of religious freedom."
But he added: "We should not forget that our society does not consist exclusively of religious sects. Ninety percent of Russian citizens or they consider Orthodox Christians … We should treat representatives of all religions in the same way – it is true, but it is also necessary to take into account the country and society in which we live. "
In a statement, the European Union strongly condemned Christensen's beliefs.
"The European Union expects Christensen to be released immediately and unconditionally. Jehovah's Witnesses, as with all other religious groups, must be able to peacefully enjoy the freedom of freedom without interference, as guaranteed by the Russian Federation's constitution, as well as by Russia's International Commitments and International Human Rights Standards. "
Prior to the ban, there were about 170,000 Jehovah's Witnesses in Russia, according to the group. Known for their door-to-door evangelization and refusal to serve in the military, Jehovah's Witnesses were founded in the United States in the late 19th century.
"The regional prosecutor's office clarified that the hell knew that Jehovah's Witnesses were banned, but he continued to hold meetings and distribute books and brochures," TASS reported.
"Jehovah's Witnesses have a well-established international reputation for being a peaceful, law-abiding citizen," said Paul Gillies, a spokesman for Jehovah's Witnesses.
"It is our hope that the Russian authorities will take this opportunity to correct the unfair decision to ban our activities that have entailed the detention of our accomplices."
Danish Foreign Minister Anders Samuelsen said on Twitter that he is "deeply concerned about the judges of Dennis Christensen."
"We again urge #Russia to respect religious freedom. The Danish Foreign Minister will continue to follow closely and help Dennis Christensen if he decides to appeal," said Samuelsen and referred to the Danish Ministry of Foreign Affairs.