The biggest proof that we are a soul existed in our heart. Whenever we were truthful 100% something within our heart fluttered all the time as if wanting to say something.
I was 100% truthful from six years of age. Something fluttered in my heart all the time. At that young age I did not know what it was all about but my quest of God was absolute. I wanted to see and meet God in this very life.
Do not know how but my ego at six years of age was zero, probably the result of previous manifestations taken by atman soul residing in my heart.
Around 8 to 9 years of age one day I finally decided to confront this voice coming from within. It was then I realized that it was voice of atman, Lord Krishna himself coming from within.
Allegorically Lord Krishna is the atman, consciousness residing in our heart all the time. It is this atman, consciousness within that manifested human form to work out its karma, remove dross impurities within. Dominated by a bloated ego we failed to hear voice of atman coming from within.
By becoming 100% truthful, by demolishing our ego in totality we can distinctly hear promptings of Lord Krishna from within, the voice of atman, consciousness all the time.
Life in human form is truly a blessing for we have a Lord Krishna within to guide us in our journey of life.
Furthermore whenever we did something wrong, the voice of atman from within prompted us not to indulge in anything unethical or immoral. I can hear this voice of atman from within all the time.
The doctrine of reincarnation, rebirth is the biggest proof that atmans existed.