Why do most Christians eat pork when Deuteronomy says not to? I am a Muslim. Pork is prohibited in my religion. I also think that it is prohibited in Christianity because of Deuteronomy chapter 14 verse 8. But why do most Christians eat pork? Is it a contradiction?

The pig is also unclean; although it has a divided hoof, it does not chew the cud. You are not to eat their meat or touch their carcasses. - Deuteronomy 14:8
Why do most Christians eat pork?
Initially, the prohibition against pork was part of the Law giving to Moses as Deuteronomy 14:7, 8 states.

However, you must not eat the following animals that chew the cud or that have split hooves: the camel, the hare, and the rock badger, because they chew the cud but do not have split hooves. They are unclean for you. 8 Also the pig because it has a split hoof but does not chew the cud. It is unclean for you. You must not eat their flesh or touch their carcasses. (NWT)

Interestingly though when here on earth, Jesus was confronted with a situation that dealt with uncleanness in Mark 7:1-8. Jesus later was explaining to his disciples the hypocrisy of the religious leaders of the time. In his explanation, Jesus made a very interesting statement:

So he said to them: “Are you also without understanding like them? Are you not aware that nothing from outside that enters into a man can defile him, 19 since it enters, not into his heart, but into his stomach, and it passes out into the sewer?” Thus he declared all foods clean.-Mark 7:18, 19 (NWT)[italics mine]

In a vision, the apostle Peter saw a large linen sheet with unclean animals. (Acts 10:9-16) In this vision, a voice spoke to him saying:

“Stop calling defiled the things God has cleansed.”-Acts 10:15 (NWT)

While this vision was to indicate the acceptance of Gentiles (non-Jews) into the congregation of God, this also corroborates Jesus's statement at Mark 7:19.
Later, the apostle Paul addressed the issue of some of those within the Christian congregation having a problem with Gentiles eating foods that were purchased in the local markets. Some of these foods were sometimes 'leftovers' of sacrifices made to false gods or idols. In 1 Corinthians 8, Paul talks about the need to not judge our fellow man about what they eat. Paul also counsels Christians to not stumble or cause problems for fellow Christians by doing things that would make them question their faith.
Ultimately, Christians are no longer under the Mosaic Law. The apostle put it plainly:

“The Law has become our tutor leading to Christ, that we might be declared righteous due to faith. But now that the faith has arrived, we are no longer under a tutor.”-Galatians 3:24, 25 (NWT)