If the Jesus of the Bible were asked, as you quoted from Qur’an 5:116-118, whether he had said, “Worship me and my mother as two gods besides Allaah,” he would certainly deny it, but not exactly as the Qur’an says. I don’t know of anyone -- in any Christian sect or otherwise -- who claimed that Mary is God, so that’s easy to deny. As for Jesus, as I’ve said, he is not claimed to be a god beside the one true God; he is the one true God.(Copied from an email conversation)How do we refute this christian who? I guess we need to tell him about Tawheed Al-Ibadah?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It seems that the statement you mentioned is part of a longer discussion, so we do not know in which context it was said so that we could comment on it and respond to the one who said it. However, our answer is going to address you, and it will be in the two points:

The first point: You undoubtedly know that the truth is what is determined in the Quran. The Quran is the truth and falsehood cannot approach it from before it or from behind it; it is the truth that does not include any lie at all. Allah Says (what means): {…and who is more truthful than Allah in statement.} [Quran 4:122]

The Christians forged the Gospel that was revealed to ‘Eesa (Jesus) which affirms Tawheed (Oneness of Allah). They changed it to Shirk (associating partners with Allah) and invented the concept of trinity, which became their belief. Afterwards, they tried to hide the contradictions and confusion in trinity, and tried to come up with interpretations for it, which they themselves do not understand, so as to claim that the trinity which Islam rejects is not the same trinity in which the Christians believe; contradiction is one of the traits of the people of falsehood.

The second point: It is only the people who have a firm and profound (Islamic) knowledge who may deal or expose themselves to misconceptions or read them. Only those who feel secure from being misguided or deviated when exposed to misconceptions can indulge in them.

Look at this wonderful and valuable advice which was offered by Shaykh Ibn Taymiyyah to his student Ibn Al-Qayyim, cited by the later in his book Miftaah Daar As-Saʻaadah (The Key to the Abode of Bliss):

“Shaykh Ibn Taymiyyah said to me when I started to ask him about one misconception after another, 'Do not make your heart, when exposed to such questions or misconceptions, absorb it like a sponge that soaks up water. Rather, let your heart be like an impermeable glass vessel, misconceptions pass by it but do not settle in it. Such a vessel sees the misconception with its [the vessel's] clearness, but repels it with its firmness. Otherwise, if your heart absorbs every misconception that passes by it, then your heart will become a settling place for misconceptions' [..] I do not believe that I have ever benefitted from any advice in repelling misconceptions more than I benefitted from this advice …” [End of quote]

Allah knows best.