Spiritualists believe that a person incarnates in order to learn. Christianity, or more correctly, the words of Jesus, teach that what you are here to learn is: to love God and other people. Buddhism, teaches that to be able to love you must become unselfish or in other words lessen the grip your ego holds over your thoughts and deeds. Buddhism gives practical techniques (meditation and mindfulness) that can help you to become unselfish.
Therefore, humility is the sign of a highly evolved soul. One should look for this characteristic when seeking a spiritual teacher.
For humans living on earth, spiritual evolution is the most important aspect of spiritual development. This is because in the afterlife you will have spiritual skills. In fact, spiritual skills will be the only skills you will have at that point. Also, in the afterlife, you will have the right beliefs because you will be able to see for yourself what the afterlife is like. However, unless you use your time on earth correctly and learn to love and to eliminate selfishness, you will not have that ability when you move into the afterlife.
While the great religions of the world teach that developing love for others is the primary objective of spiritual development, it is not enough to say this without some instruction on how to develop love. Our biological nature puts up many obstacles against love. People hear the beautiful words of the great teachers and then find that it is impossible to live according to their beliefs. This damages people psychologically and brings disrepute to preachers and followers alike.
Therefore it is important for humankind to have an explanation of how to develop love. Love arises spontaneously when hatred and anger and other forms of selfish and negative thought are absent.
The way to eliminate selfishness through meditation can be found in the page on meditation. If you practice meditation daily, then gradually over the years, without straining to be perfect, you will become less and less self centered and a natural love for others will arise within you. The chapter on Short Topics has more On The Purpose of Life.