Indeed, those who have believed then disbelieved, then believed, then disbelieved, and (4:137)

Almuntakhab Fi Tafsir Alquran Alkarim

Indeed, those who conformed to Islam then turned renegades, then again conformed to Islam and again went over from Islam and sank deeply in disbelief under the unjustifiable vexations of their minds and spirit shall be undone past all retrieve whichever way they turn. Never shall Allah forgive them nor guide them to the path of righteousness

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(4:137) Allah will neither forgive nor show the right way to those who believed, and then disbelieved, then believed, and again disbelieved, and thenceforth became ever more intense in their disbelief. *168

Indeed, those who have believed then disbelieved, then believed, then disbelieved, and meaning

*168). This refers to those for whom religion is no more than an object of casual entertainment, a toy with which they like to play as long as it suits their desires and fancies. One wave carries them to the fold of Islam and the next away to that of disbelief. Whenever Islam appears to suit their interests they become Muslims; and when the glamorous visage of the god of utility leaps up before their eyes they rush off to worship it. To such people God holds out neither the assurance of forgiveness nor of direction to true guidance. The statement that such people 'became even more intense in their disbelief refers to those who are not content with not believing themselves, but also try to undermine the faith of others and to persuade them to disbelief, who engage in secret conspiracies as well as overt activities against Islam, and who devote their energies to the struggle aimed at exalting disbelief and degrading the true religion of God. This is a higher degree of disbelief, involving the progressive heaping of crime upon crime. It is obvious that the punishment for this must be greater than for simple disbelief.
 

Indeed, those who have believed then disbelieved, then believed, then disbelieved, and meaning in Urdu

رہے وہ لوگ جو ایمان لائے، پھر کفر کیا، پھر ایمان لائے، پھر کفر کیا، پھر اپنے کفر میں بڑھتے چلے گئے، تو اللہ ہرگز ان کو معاف نہ کرے گا اور نہ کبھی اُن کو راہ راست دکھائے گا