Those who want to draw closer to God must first do this.
St. Catherine of Siena was an influential saint from the 14th century, and is known and beloved by many for her holiness and tenacity of spirit. She led a profound interior life as a member of the Third Order of St. Dominic and wrote many of her insights in what is now called her Dialogues.
One piece of advice she wrote about was the first step a soul must take in the spiritual life.
The soul, who is lifted by a very great and yearning desire for the honor of God and the salvation of souls, begins by exercising herself, for a certain space of time, in the ordinary virtues, remaining in the cell of self-knowledge, in order to know better the goodness of God towards her.
She explains that this path of knowledge not only revolves around knowing better who you are, but also who God is and his role in your life.
Furthermore, St. Catherine wrote down words of Jesus that were spoken to her in a private revelation that explain how self-knowledge and knowledge of God are intimately connected, with one complementing the other.
I reply that this is the way, if you will arrive at a perfect knowledge and enjoyment of Me, the Eternal Truth, that you should never go outside the knowledge of yourself, and, by humbling yourself in the valley of humility, you will know Me and yourself, from which knowledge you will draw all that is necessary.
St. Catherine adds that knowledge is always the first step in the spiritual life and naturally leads a person to the next stage.
This she does because knowledge must precede love, and only when she has attained love, can she strive to follow and to clothe herself with the truth.
Her advice is echoed in the Prologue of the Catechism of the Catholic Church.
God draws close to man. He calls man to seek him, to know him, to love him with all his strength.