A firm faith in Heavenly Father, Jesus Christ, and the Holy Ghost is a requirement to succeed in this life, to return to Heavenly Father in the afterlife, and to become a god yourself. Faith is the assurance of things which we cannot see but are true. It is faith that causes a farmer to plant seeds with the hope they will produce grain. Having faith in Jesus Christ means completely trusting his power, intelligence, and love, and believing that he understands all things even if you do not.
Jesus will work great miracles through you according to your faith. Members of the Church with enough faith have performed the mighty deeds Jesus once did. Unwavering faith can stop the mouth of lions and keep fiery flames from harming you. Such faith can dry up rivers and seas or bring an end to droughts. It can heal the sick or bring about heavenly manifestations of angels.
One can have belief, but lack faith. Faith is vitalized, vivified, living belief. To develop it, you must be active in all of your duties as a member of the Church of Jesus Christ of Latter-day Saints. No member of the Church will even be in danger of losing their faith in the Church so long as they remain prayerful, humble, and obedient to their duties.