The Lord expresses His gratitude to Heavenly Father that His disciples have been purified because of their faith. He goes on to express His desire for the purification of all those who believe in faith on the words of His disciples. Purification, the process of becoming clean and holy is made possible through the Atonement (see Alma 5:21; 13:11). Through fasting and prayer we can become strong in our humility and firm in our faith—so much so that we are filled with joy even to the purification and sanctification of our hearts, which transformation comes because we yield our hearts to God (see Helaman 3:35). We become sanctified by the power of the Holy Ghost (see Alma 5:54; 13:12; 3 Nephi 27:20). As we seek to take upon ourselves the divine nature of Christ (see 2 Peter 1:3–8) and pray with all the energy of heart that we will be filled with charity—the pure love of Christ—we will have grow within us the hope that we shall be like the Lord when He appears, even pure as He is pure (see Moroni 7:48). We can be purified by the Holy Ghost as we exercise our faith in Jesus Christ.