COMMENTARY on 29:46
A. Yusuf Ali:

Translation:
And dispute you not with the People of the Book, except with means better 3472 (than mere disputation), unless it be with those of them who inflict wrong (and injury): 3473 but say, "We believe in the revelation which has come down to us and in that which came down to you; Our Allah and your Allah is one; and it is to Him we bow (in Islam)." 3474
Commentary:

3472  Mere disputations are futile. In order to achieve our purpose as true standard-bearers for Allah, we shall have to find true common grounds of belief, as stated in the latter part of this verse, and also to show by our urbanity, kindness, sincerity, truth, and genuine anxiety, for the good of others, that we are not cranks or merely seeking selfish or questionable aims.

3473  Of course those who are deliberately trying to wrong or injure others will have to be treated firmly, as we are guardians of each other. With them, there is little question of finding common ground or exercising patience, until the injury is prevented or stopped.

3474  That is, the religion of all true and sincere men of Faith is, or should be, one; and that is the ideal of Islam.

 

Muhammad Asad:

Translation:
And do not argue with the followers of earlier revelation otherwise than in a most kindly manner - unless it be such of them as are bent on evildoing 42 and say: “We believe in that which has been be­stowed from on high upon us, as well as that which has been bestowed upon you: or our God and your God is one and the same, and it is unto Him that We [all] surrender ourselves.”
Commentary:
42  Sc., "and are therefore not accessible to friendly argument": the implication being that in such cases all disputes should a priori be avoided. As regards religious discussions in general, see note 149 on 16:125.