There are two ways we learn things in life:
one is by obtaining information, which is a theoretical way, and
the other is by experience, that’s the practical way.
The mother may constantly teach, and at times, even yell at her baby for playing with fire. However, the baby learns the dangers of fire only after touching it and sensing the heat. So, the practical way is always a surer way. Every living being learns from his mistakes. However, it is up to us, how quickly we accept our mistakes and use them constructively to learn the right lessons and make ourselves a better person. With a tendency to get depressed and feel hopeless with mistakes, one may not be able to go too far.

You say you feel hopeless for having committed the unpardonable sin.
So, first of all, let’s understand the science behind how our actions happen in life.
Our thoughts, words and actions in this life are nothing but a pure discharge of whatever we charged in previous life. For example, a thief is seen stealing money in this life. The act of stealing is really not in his hands today. This stealing is happening due to the intent he had harnessed in his previous life, 'stealing is the best and easiest way of earning in life.' This intent that he had was the seed (the charging point of karma). Consequently, in this life, all the circumstantial evidences come together to bring about his karma of stealing into fruition.

Heart-felt repentance in combination with firm resolution to never repeat the mistake will set us free
Now, after looting, based on his inner development and surroundings,
he may feel happy with his act of stealing and thus sow further new seeds to steal once again in the next life,
he may repent for committing the sin of stealing and thus wash away the old sin, and also vow ‘never to steal again’ so that such sin is not committed again.
When we understand this science, we will not feel hopeless for our wrong actions, but instead shall have the enthusiasm to rectify our mistakes, improve, and move ahead in life.

Every sin is pardonable from the moment we realize and accept, ‘It is my mistake!’
Some sins seem to be unpardonable as it might have hurt others, and you may be thinking, 'how did I do it!' But the fact is that every sin is pardonable from the moment we realize and accept that it is my mistake. On recognizing our mistake, we should always practice repentance; but at the same time, not get stuck up at the stage of repentance. We will ask for forgiveness for the hurt caused to others and also ask God for strength to never repeat these errors.

Sometimes, the situation may be such that it may not be possible to ask for forgiveness in person. In such cases, we can pray to the Lord (Soul) within that person(s) to forgive all our mistakes and give us the strength to never repeat them. When we keep doing this repeatedly, we will find that our heart becomes light, and the other person automatically becomes willing to forgive and forget our mistakes.

Would you like to know another excellent way to come out of all the sins and worries in life?
Knowing the Real Self i.e. ‘who am I’ in reality, will free you from all worldly sorrows!

You may know the story of a lion's cub that mistakenly grew up with a flock of goats and feared other lions. What did it take for the cub to realize who it was, in reality? It only needed to realize who am I, which changed its belief and behavior.

Similarly, you too, after Self-Realization, shall realize how ‘I am a Pure Soul and am totally separate from the one who has committed the unpardonable sin.’ Gnani, the Enlightened One, can make us realize our real Self. Once you attain Self-realization, you realize that you are not the one who feels hopeless. You can remain separate and thus come out of the perennial cycle of sowing seeds and seeds of karma (charging) and suffering the fruits of such karma (discharge).

'Blessed is the event that breaks worldly ties'. You can attain freedom from the worldly bondages in this very life. So, let your mistake turn into a boon by inspiring you to attain Self-Realization from Gnani Purush Dada Bhagwan and thus changing your life into a fountain of eternal bliss. Wish you goodluck!!

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Author's Bio: 

Ambalal M. Patel was a civil contractor by profession. In June 1958, spontaneous Self-Realization occurred within Ambalal M. Patel. From this point on, Ambalal became a Gnani Purush, and the Lord that manifest within him became known as Dada Bhagwan. A Gnani Purush is One who has realized the Self and is able help others do the same. Param Pujya Dada Bhagwan used to go from town to town and country-to-country to give satsang (spiritual discourse) and impart the knowledge of the Self, as well as knowledge of harmonious worldly interactions to everyone who came to meet him. This spiritual science, known as Akram Vignan, is the step-less path to Self-realization.