You cannot achieve peace and happiness in your life without developing the practice of honesty in relating with others.
Honesty with others requires honesty with oneself. Honesty with oneself requires self knowledge, self acceptance and the practice of self improvement, or evolution.
We are currently living in a popular culture in which alcoholism and distaste for self exploration are in vogue. Denial is rampant. Denial of real financial worth. Denial of responsibility for debts. Denial of responsibility for children's education. Denial of responsibility for the welfare of the society as a whole.
Self exploration, through meditation, intimate relationships, psychotherapy or other tools, is absolutely necessary to achieve self knowledge and honesty. It is necessary to take regular hard looks at your motives, emotions, reactions and hopes. Doing this throughout your day and your life will deepen your understanding of your life.
Self acceptance is the practice of looking at the results of your self exploration and accepting those results as who you really are. Warts and all!
Self improvement entails working from your real self image and daily working to make yourself more loving, more compassionate, healthier and more generous. It also can entail making yourself less selfish and less obsessed with your own needs at the same time.
"Spiritual" practices, based in sanctimonious and ethereal rites, are useless when seeking happiness and peace in one's life. Incense and fancy dress never made anyone a better or happier person. Hard work does. And it is best to start working right now.