Quran 8:39 – “And fight with them until there is no more fitna and religion should be only for Allah”
Let’s read a better translation for Q. 8:39,
Pickthall Quran 8:39 And fight them until persecution is no more, and religion is all for Allah. But if they cease, then lo! Allah is Seer of what they do.
The ‘fitna’ mentioned in the above verse (Q 8:39) means persecution, oppression, as shown by Pickthall’s Quran translation. When the verse says, “And fight with them until there is no more fitna”, it gave Muslims permission to fight until there is no more persecution (fitna), 1400 years ago. Critics elude to this passage claiming that the Arabic word ‘fitna’ used here does not really mean ‘persecution’ or ‘oppression’, according to these self-made scholars who have no formal education on Islam, to them the word ‘fitna’ means ‘unbelief’. When it is used in that sense, they’re trying to portray the verse to non-Muslims who don’t know the Arabic language that the passage sanctions Muslims to fight non-believers on account of them of being non-Muslim. However, when we consult Arabic-English dictionaries critics’ deception is exposed. In the following article which can be seen here, I have provided many Muslim and non-Muslim scholarly evidences that the Arabic word ‘fitna’ means, ‘persecution’, ‘oppression’.
Non-Muslim Quran Translations for 8:39
Arthur John Arberry Quran 8:39 Fight them, till there is no persecution and the religion is God’s entirely; then if they give over, surely God sees the things they do…
George Sale Quran 8:39 And fight them until there is no persecution and religion is wholly to God. But if they desist, then surely God is Watchful of what they do.
“39 I.e., until man is free to worship God. Cf. the identical phrase in 2:193, and the corresponding note. Both these passages stress self-defence – in the widest sense of this word – as the only justification of war.” 
The Holy Qur’an Arabic Text With English Translation & Short Commentary – Malik Ghulam Farid:
“1120. Muslims were enjoined to fight till religious persecution had ceased and men were free to practice the religion of their choice. Islam undoubtedly is the greatest upholder of freedom of conscience (2:194).” 
The Holy Quran Arabic Text with English Translation, Commentary and comprehensive Introduction – Maulana Muhammad Ali:
“39a That is, desist from fighting and put an end to their mischief, God’s decree of punishment will not be executed. God sees what men do, and if they mend their ways, He will not punish them. The state of religious liberty which Islam aimed at is put tersely in the two opening statements – ‘there is no more persecution and all religions are for Allah’.
40a. If they return to fight, then Allah will protect the Muslim community, helping them against their enemy, as He is their Patron and Helper.” 
“Shirk Or Persecution – What does The Word Fitna Mean?”
 The Message of The Quran Translated And explained by Muhammad Asad
 The Holy Qur’an Arabic Text With English Translation & Short Commentary By Malik Ghulam Farid, page 366
 The Holy Quran Arabic Text with English Translation, Commentary and comprehensive Introduction [Year 2002 Edition] by Maulana Muhammad Ali, page 385