Bhagavad-gītā As It Is · Text 6.43
Spiritual effort is not lost
तत्र तं बुद्धिसंयोगं लभते पौर्वदेहिकम् ।
यतते च ततो भूय: संसिद्धौ कुरुनन्दन ॥ ४३ ॥
tatra taṁ buddhi-saṁyogaṁ
labhate paurva-dehikam
yatate ca tato bhūyaḥ
saṁsiddhau kuru-nandana
On taking such a birth, he revives the divine consciousness of his previous life, and he again tries to make further progress in order to achieve complete success, O son of Kuru.
Read Śrīla Prabhupāda's purport on Vedabase.io