A Brief Word on Missionaries
We encourage all Du’aat not to actively involve themselves with missionaries this is because the environment is not conducive to serious discussion on the truth. They are there to spread their message and you are there to spread the truth.
Therefore even when they are shown the error of their ways they do not use reason – instead they go around in circles continuing the debate – a method known as Gish Galloping. They have given up all hope of defeating Islam therefore by occupying you they prevent you from giving Da’wah to someone else.
Therefore a most befitting reply and closure to any episode of dialogue between them would be as below while maintaining composure in all regards:
“And [the believers among] those to whom We have given the [previous] Scripture rejoice at what has been revealed to you, [O Muhammad], but among the [opposing] factions are those who deny part of it. Say, "I have only been commanded to worship Allah and not associate [anything] with Him. To Him I invite, and to Him is my return." (Noble Quran 13:36)
“You will surely be tested in your possessions and in yourselves. And you will surely hear from those who were given the Scripture before you and from those who associate others with Allah much abuse. But if you are patient and fear Allah -indeed, that is of the matters [worthy] of determination.” (Noble Quran 3:186)
However a special note for anyone who seeks to be extremely polite in the face of abuse against Islam or tries to please those factions who attempt to ridicule the Muslims or their message, so that they may warm to them and accept them:
“And never will the Jews or the Christians approve of you until you follow their religion. Say, "Indeed, the guidance of Allah is the [only] guidance." If you were to follow their desires after what has come to you of knowledge, you would have against Allah no protector or helper.” (Noble Quran 2:120)
How should we behave towards the older scriptures in their current form?
This issue is often one of confusion and debate amongst well to do Muslims. How do we tackle the scriptures and what they say? Well, the position we strive to take is one that inclines towards the Quran and Sunnah – simply put: we accept that there were previous revelations NOT because they have followers in their millions today but because the Quran confirms that the previous messengers received revelation. Therefore we believe in the original revelations of the book of Abraham, Torah of Moses, Psalms of David and Gospel of Jesus; peace be upon them all. However due to various verses in The Quran we see that the people of these Books had either forgot parts or changed the verses (intentionally & unintentionally) and therefore the books we have before us today are not representative of the pure word of God.
So woe to those who write the "scripture" with their own hands, then say, "This is from Allah ," in order to exchange it for a small price. Woe to them for what their hands have written and woe to them for what they earn. (Noble Quran 2:79)
And indeed, there is among them a party who alter the Scripture with their tongues so you may think it is from the Scripture, but it is not from the Scripture. And they say, "This is from Allah ", but it is not from Allah. And they speak untruth about Allah while they know. (Noble Quran 3:78)
And [mention, O Muhammad], when Allah took a covenant from those who were given the Scripture, [saying], "You must make it clear to the people and not conceal it." But they threw it away behind their backs and exchanged it for a small price. And wretched is that which they purchased. (Noble Quran 3:187)
So for their breaking of the covenant We cursed them and made their hearts hard. They distort words from their [proper] usages and have forgotten a portion of that of which they were reminded. And you will still observe deceit among them, except a few of them. But pardon them and overlook [their misdeeds]. Indeed, Allah loves the doers of good. And from those who say, "We are Christians" We took their covenant; but they forgot a portion of that of which they were reminded. So We caused among them animosity and hatred until the Day of Resurrection. And Allah is going to inform them about what they used to do. (Noble Quran 5:13-14)
Therefore we prefer not to cherry-pick verse against verse from their scriptures but instead opt to highlight the unreliability of their scriptures (in their current form).
There are obviously occasions depending on context and audience where the use of their scripture to highlight the error of their ways is used but this should not be an option from the outset. We argue that to try and ascertain the teachings of God from sources that are unreliable by their own scholarly admission (and also by Quran) is a futile and obviously unfaithful objective. After all why use something inferior (current state of scriptures) to describe something superior (God)?
The best position we take with regards to the teachings found in the Books of the People of Scriptures is as below:
Narrated Abu Huraira (RA): The people of the Scripture (Jews) used to recite the Torah in Hebrew and they used to explain it in Arabic to the Muslims. On that Allah's Apostle (salallahu alayhi wa sallam) said, "Do not believe the people of the Scripture or disbelieve them, but say: --"We believe in Allah and what is revealed to us." (Bukhari Volume 6, Book 60, Number 12)
Thereby in following the instruction of the Prophet (salallahu alayhi wa sallam) we use the Quran as the measure or criterion to determine the right and wrong from what they present by way of discourse.
On a final note regarding missionaries, be advised that they will deliberately misquote texts from The Quran to highlight their beliefs as correct, so always double check what they quote.