Hi Samuel,
 

There are three types of the spirit to consider, to find God’s True Ways.
 

Spirit is just an ancient word for Soul. And a human Soul consists of thoughts, memory and personality, you create during your human life. After your vessel dies, your human Soul still exists in the, for most unknown, In-between life. Living as a human Soul an In-between life, between being a Man and your Godly Soul. Your human Soul is part of your Godly Soul, called by many the Holy Spirit. The Godly Soul is part of God, therefor it is called Godly or Holy. Whether you believe in God or Not, doesn’t matter, it is for ALL the same.
 

When you are rich in spirit, you have an intelligent, scientific and very active mind. What means, a person formulates all the time new thoughts. This type of person desires to evolve Man´s physical thoughts and ways, and is mostly living by an ego perspective. Biblical called, “living in the flesh.” When you are rich in spirit you carry a Huge Responsibility, to formulate the right thoughts based on God´s True ways. When you do Not, but formulate wrong thoughts and wrong ways, which are Not, good and loving for yourself AND at the same time good and loving for Everyone else AND at the same time good and loving for Nature, then you shall create negative consequences in this human life and certainly in your In-between life (=afterlife), as a human Soul in the Repentance phase by Works. Where you still have to purify your human Soul. To purify your human Thoughts, Memories and Personality, to fit into the only loving, godly and harmonious Godly Soul. That is the reason, why Man has to purify their human Soul, their thoughts, memory and personality. What defines our purpose in a human life. Not to live in the flesh, but to evolve Man’s Soul.
 

When you are poor in spirit, then you are Not constantly trying to evolve your physical thoughts and ways based on an ego perspective, into new thoughts and new ways. You are only trying to live a simple and good life and be good for others and Nature too. You are focusing on harmony and love within yourself, between each other and with Nature. You love simple thoughts and simple ways, to be good in life for Everyone and Nature. What is the basis of being blessed, or called becoming enlightened. Enlightenment means to have purified your human Soul, thoughts, memory and personality.
 

The Real Purpose in life is to become enlightened in spirit. Not to choose constantly thoughts and ways, that enhance physical evolvement. Not to choose to live by ego, lust, violence and pride. But to live and understand the spiritual way or called Soul’s way, or called God’s True way of evolving in life. To become a perfect harmonious being, called a Saint, who has perfected their thoughts, memory and personality of their human Soul into Love and Harmony.  And chooses Only what is good and loving for themselves AND at the same time what is good and loving for Everyone AND at the same time what is good and loving for Nature. To live a harmonious human life, as Life was meant by God to be. To create a small Heaven on Earth, what is called figuratively “a Temple” of Heaven on Earth. To live life, as it was meant to be.
 

Your question;
Matthew 5:3 says blessed are the poor in spirit. How do I become poor in spirit so that I can be blessed?
 

Live by God’s True Ways, which are Not based on any scripture or ideology of Man, but on the True Works and Will of God, explained by Christ, the Messiah.
 

See possessions as experiences. Understand that in your human life, you flow from one experience into another experience. Some are good and happy, and some are Challenging experiences. Make sure you handle challenging experiences, called Lessons of Life, which are all negative situations or negative persons appearing in your life or in yourself, still with harmonious thoughts. Harmonious thoughts are Good, Loving, Positive, Righteous, Calm, Forgiving, Peaceful, Supportive, Sharing and Equal thoughts for everyone.
 

Let go of Ego, Lust, Violence and Pride, and live your life, and enjoy your life to handle the challenging Lessons of Life with Harmonious and Loving thoughts. When you live as a Saint, a harmonious human being, you dissolve all negative emotions and bad and sad feelings from your life. To make room for True Happiness rising from within, no matter what is happening in your human life.
 

To provide in life and to obtain the basic needs in life is a challenging experience, to create within God’s True Ways.
 

Understand that your Real Purpose in Life is, that you have to learn over time to purify your human Soul in life, your thoughts, memories and personality into pure love and harmony, to fulfill your purpose in life.
 

Remark; Love is pure Harmony and Harmony is pure Love.
Sometimes, I use the same kind of Words to emphasize the intention of the Words.
 

To be poor in thoughts, is to use your thoughts to grow spiritually, to grow your human Soul, to grow and evolve your human Thoughts into Harmony. To use these words as bread for your human Soul. To consume the Words, to seal the Words what means to study and memorize the Words, and THEN to LIVE the Words.
 

To be enlightened in thoughts, is to understand God’s True Will and Works, that shall guide you into a perfect harmonious human life. What literally means you are Ready. To be Ready means to have lift your human Soul, to be protected, to be able to endure and to survive the nearing unfolding dire ordeals on Earth and to enter the Age of Harmony (Biblical called the Age of Kingdom) on a New restored Earth. Where a new civilization shall be created who live without Sin, and live without almost any Ego. And you are Ready when you vessel would die, that you are able to merge your harmonious human Soul into the harmonious Godly Soul and can almost instantly return home, to Heaven. And you do Not have to experience a “second death” in the repentance phase in your In-between life. Because, you have already dissolved all your Lessons of Life, by harmonious thoughts.

By living God´s True Ways you have fulfilled the purpose of life in the School for our Souls on Earth.
 

For those who did Not purify their human Soul’s as Man on Earth, they shall ALL have to purify their human Soul in their real In-between life. Which is explained many times in detail in this website available for everyone. To guide and to help to Save your human Souls. 

It is what it is, nothing more and nothing less.
 

Life is all about thoughts and choices.

Choose well.