It is achieved through God’s grace

Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect. (Romans 12:2 ESV)

 We’re called to develop a scriptural mindset so that our values, desires, and morals are based on the teachings of the Bible rather than on society’s norms.
 Godliness also calls for transforming our will to be in alignment with His will as revealed in Scripture. We embrace what God wills and say no to what defies Him.
 Transformation to Christlikeness is holistic in that it transforms our total person. It’s a process which begins at the time of our salvation and continues throughout our life. It is achieved through God’s grace and the transformative work of the Holy Spirit, but this doesn’t mean that God transforms us into Christlikeness with no effort on our part. When we are serious about being more like Jesus, we of course pray for the Lord to change us, but we also make decisions that move us toward holiness and we put those decisions into practice.
 Christlikeness calls us to take a stance against the negative actions, impulses, and thoughts in our hearts and minds that lead to sin; and to embrace the virtues, values, and morals that reflect God’s nature. —Peter Amsterdam [1]

 Men are free to decide their own moral choices, but they are also under the necessity to account to God for those choices. —Aiden Tozer (1897–1963)

[1] Anchor In Pursuit of Holiness