Once a person has been deceived by Satan - the father of lies - into believing they are licensed by their god to lie even a little, it is obvious the lying will know no limits. From expiating oaths to engaging in Dawah.

Taqiyya according to Sunni Muslim theologian Abu Ha-med Mohammad ibn Mohammad al-Ghazzali:

“Speaking is a means to achieve objectives. If a praiseworthy aim is attainable through both telling the truth and lying, it is unlawful to accomplish it through lying because there is no need for it. When it is possible to achieve such an aim by lying but not by telling the truth, it is permissible to lie if attaining the goal is permissible..., and obligatory to lie if the goal is obligatory. ...One should compare the bad consequences entailed by lying to those entailed by telling the truth, and if the consequences of telling the truth are more damaging, one is entitled to lie…”

For example Dawah, or proselytizing others into Muhammad's anti-religion, is considered by most Muslim scholars to be an "obligatory" "goal".
https://www.google.com/#q=Dawah+obligatory+goal
Since Islamic so-called "tradition" is scripture-contrary, history-contrary, archaeology absent and a geographical impossibility, it goes without saying that it would be more than difficult to convince someone they should join the fold without lying (like the Deedat and Estes examples in this thread), when questions arise.