For pre-schoolers, high school books are “just books with more words”; same way when ever we read scriptures like Bhagavad Gita, we understand as per our level of understanding.
That is the reason, people recommends Bhagavad Gita to be read multiple times, so that one can understand deeper and deeper meanings as our maturity grows with every iteration.
Additionally, to help us grow our spiritual maturity, there are some techniques available, like Yama-Niyama from Patanjali Yogasutras.
Yama :
In this person deals with mastering control over mind.Focus here is on how we conduct our lives. Five areas are identified by Rishi Patanjali:
1. Ahimsa : Not having an intent to hurt others, through speech, physically or any other means.
2. Satya : Speaking truth (but not with the intention of hurting someone).
3. Asteya : Not eyeing others possessions, giving up jealousy or need to show-off.
4. Brahmachaya : Denial of sensory pleasure beyond what is allowed in shastras, including avoiding rajas/tamas food.
5. Aparigraha : Not wanting create possession beyond need. Possession are important, but we don’t need 10x of everything,
Niyama :
In this person sets and follows rules, for everyday life. This brings stability and routine to a person’s life, and constant practice of this would help person to calm down his/her mind further.
1. Swacha : Cleanliness, both body and mind.
2. Santosha : Staying content in what is available. While one should strive for progress in life, but while doing that we don’t need to be restless. We can progress far better while staying calm and content.
3. Tapa : Performing austerity, controlling senses, upwasas etc
4. Swadhyaya : Reading spiritual literature, also staying in the company of like minded people.
5. Ishwar paridhana : Surrendering to god, regular mantra chanting, regular vratas etc.
To start with, one can choose few of this, and do a regular abhyas (practice). We can then grow the scope as we get more comfortable.
Many of us already follow some of these like Upwasa, Vrata, Mantra chanting etc. Let us use them specially to grow our spiritual maturity.
All the Best!