Philippians 1:9-10 ESV
And it is my prayer that your love may abound more and more, with knowledge and all discernment,  so that you may approve what is excellent, and so be pure and blameless for the day of Christ,
Our sanctification is another part of His grace towards us. He exhorts us to participate in it. The Apostle Paul really waxes poetic about it in his pastoral epistles; firstly citing himself as an example of God’s perfect mercy towards him to show how gracious and patient He is towards us who believe. (1 Timothy 1:16) Then, Paul exhorts us in the same letter to pursue godliness not only as a means of grace for the present but also as a way to be ready for the life to come. (1 Timothy 4:7-8)
Our participation in sanctification comes with a warning because we can easily get out of balance with the process. If we attempt to succeed by self effort, we will become puffed up with pride and all will be in vain. On the other hand, if we sit back on our laurels and wait for God to perfect us, we may be penitently sorry later when Christ rewards each of us who believe for what we have done in Him in this life. The key, I guess, is to abide in the Vine of Jesus Christ. (John 15:4-5)
Our motives in the process of sanctification always need to be self-examined because God will prove us in every way as He seeks to conform us to the image of His one and only Son. Legalists fall into the trap of pride and the fruit thereof is corrupt. Legalists are prey to the mentality that “I do _____ and, therefore, I deserve _____.” When the pronoun “I” becomes a part of the motive, then it is carnal and sinful. However, if you are bent towards godliness because you want to honor the One who paid it all for you, then it is Spiritually motivated and pleasing to Him.
God is most pleased when we honor Him with all He is and who He is. We cannot bring anything in and of ourselves to please Him except our praise, worship, and awe.