When one prays to God one feels a delight in the senses such as a warm feeling, great fervor, visions, etc. These are all candy from God to turn one's heart toward Him. It's like showering gifts upon someone to attract their attention. The beginner at prayer finds himself experiencing greater delight in praying to and serving God than in his former sinfulness. Thus, little by little, the person detaches himself from sin and begins to cling to God.
Serious sins become a thing of the past.
The important thing I wish to express here is to encourage people to begin the journey of prayer. Begin with a good Confession and then nuture one's soul by reading the Holy Bible, praying the Holy Rosary, attending Holy Mass, avoiding occasions of sin - in short, make an effort to remain in God's grace. Then, and only then, can one begin a journey of prayer, a relationship with God.