Arjuna asks: "What happens to the person who attempts & fails (for mastery is difficult & not all ends can be foreseen).
Are all their exertions useless, is it any good beginning an effort which one may not be able to complete?"

Krishna: "Neither in this life nor hereafter is there
loss for him; for never does anyone who does good, tread the path of woe."

Any setback is only temporary(even failure, is a success), he who starts well, reaches the end, & no sincere attempt ever goes without its reward.

Eckhart says: 'If thou do not fail in intention, but only in capacity, verily, thou hast done all in the sight of God.'

Goethe: 'Whoever strives & labors, him may we bring redemption.'

-From the Bhagavadgita
Commentary by S.Radhakrishnan