Bhagavad Gita 6.40 · Krishna
No good effort is ever lost
पार्थ नैवेह नामुत्र विनाशस्तस्य विद्यते।
न हि कल्याणकृत्कश्चिद् दुर्गतिं तात गच्छति॥
śrībhagavānuvācapārtha naiveha nāmutra vināśastasya vidyatena hi kalyāṇakṛtkaścid durgatiṃ tāta gacchati
Partha, there is no ruin for such a one, not here and not beyond. No one who does good, My dear, ever comes to harm.
What it means
Krishna answers with one of the tenderest lines in the Gita. Na hi kalyana-krit kashchit durgatim tata gacchati. No one who does good ever comes to a bad end. He even calls Arjuna tata, my dear, my child. Sincere effort is never lost, in this life or any other.
The story
Krishna rarely uses such an intimate word. Tata is what a father calls a son. Arjuna's fear has touched Krishna's heart, and he answers with pure love.
In your life
Think of a teacher whose student failed an exam but grew into a kind, capable adult. Nothing they gave was wasted. Remember your past efforts that didn't seem to work. They still count.
No good effort is ever lost.