namaH to all.
This is also a shlokaH from bhagavadgItA. This is the second of 8 shlokAH that svAmi-shivAnandaH has identified as the promise of bhagavadgItA to the uninitiated. (With the first shloka itself, one ceases to be uninitiated!)
क्षिप्रं भवति धर्मात्मा शश्वच्छान्तिं निगच्छति ।
कौन्तेय प्रतिजानीहि न मे भक्तः प्रणश्यति ॥
Having a good thought causes one to have done some good, as seen in the 1st of 8 shloka-s. That good thought paves the way for him to become a classified as dharmAtmA, and this happens fast - क्षिप्रं भवति धर्मात्मा । And, by nature, he transforms into a भक्तः - on who identifies with भगवान्. This भक्तः attains everlasting peace - शश्वत्-शान्तिं निगच्छति । And, भगवान् assures - that such a भक्तः never comes to ruin - न मे भक्तः प्रणश्यति । कौन्तेय प्रतिजानीहि - Hey Arjuna, know this to be a promise - though it is addressed to Arjuna, it is a reference to all.
Thus, one good thought itself is a catalyst for everlasting peace. May the world never be at a state where even a good thought becomes rare!
shubham
vidyA