The Quran

الَّذينَ أُخرِجوا مِن دِيارِهِم بِغَيرِ حَقٍّ إِلّا أَن يَقولوا رَبُّنَا اللَّهُ ۗ وَلَولا دَفعُ اللَّهِ النّاسَ بَعضَهُم بِبَعضٍ لَهُدِّمَت صَوامِعُ وَبِيَعٌ وَصَلَواتٌ وَمَساجِدُ يُذكَرُ فيهَا اسمُ اللَّهِ كَثيرًا ۗ وَلَيَنصُرَنَّ اللَّهُ مَن يَنصُرُهُ ۗ إِنَّ اللَّهَ لَقَوِيٌّ عَزيزٌ

Muhammad Asad

those who have been driven from their homelands against all right for no other reason than their saying, "Our Sustainer is God!" For, if God had not enabled people to defend themselves against one another,¹ [all] monasteries and churches and synagogues and mosques - in [all of] which God's name is abundantly extolled - would surely have been destroyed [ere now].² And God will most certainly succour him who succours His cause: for, verily, God is most powerful, almighty,

Lit., "were it not that God repels some people by means of others" (cf. the identical phrase in the second paragraph of 2:251).
The implication is that the defence of religious freedom is the foremost cause for which arms may and, indeed, must - be taken up (see 2:193 and the corresponding note 170), or else, as stressed in the concluding clause of 2:251, "corruption would surely overwhelm the earth".