1 Thessalonians 5:23-24
Sanctification is the process God uses to conform believers to the image of His Son. The writers of Scripture employed images that speak of the Father's shaping work in the life of His saints. Isaiah, for example, compared the Lord to an artist making pottery: "We are the clay and You our potter; and all of us are the work of Your hand" (64:8). Some of the tools He utilizes to mold and perfect His creations are...
The Bible. The psalmist described God's Word as "a lamp to my feet and a light to my path" (119:105). The Holy Spirit illuminates what we read so that we can come under conviction and grow in our faith.
The church. As part of Christ's body, we learn of God's ways from the pastor and teachers who've been called to minister. The Father also calls His children to fellowship together (Heb. 10:25), in part so He can use them in each other's sanctification process. Not only that, but there are Christians at church who will encourage their brothers and sisters in times of trouble--and hold them accountable when they miss the mark.
Suffering. God freely offers us solace and help during times of difficulty, but He also uses our painful circumstances to shape us. When we submit to the work He is doing, we emerge from our struggles looking more Christlike than ever before.
From the moment a person places trust in the Lord Jesus Christ, God's transforming work of sanctification will be ongoing throughout this life. As children of the King, we should long to glorify our Father by faithfully reflecting Him. To do that, we must yield to His tools of sanctification.