Omni 1:26

26 And now, my beloved brethren, I would that ye should come unto Christ, who is the Holy One of Israel, and partake of his salvation, and the power of his redemption. Yea, come unto him, and offer your whole souls as an offering unto him, and continue in fasting and praying, and endure to the end; and as the Lord liveth ye will be saved.

Helaman 3:35

35. Nevertheless they did fast and pray oft, and did wax stronger and stronger in their humility, and firmer and firmer in the faith of Christ, unto the filling their souls with joy and consolation, yea, even to the purifying and sanctification of their hearts, which sanctification cometh because of their yielding their hearts unto God.