Who shall we be, when we see Christ? We will one day be changed into the very likeness of Jesus. "We shall be like Him, for we shall see Him as He is" (1 John 3:2). That's the work of God in our lives. Until that day, the Lord is still working in us. Remember, we are a work in progress.
Life is always changing, and so are we. That means we are becoming who we shall be. We are not there yet. God is still working on us, as believers in Jesus Christ. God knows who we shall be, but we are not there now.
Every believer is becoming more and more like Jesus, but we have a long way to go. "For whom He foreknew, He also predestined to be conformed to the image of His Son" (Romans 8:29). That is when we are glorified in Christ at his coming. As far as God is concerned, we are still a work in progress.
Sanctification means we are becoming who we shall be in Christ. We are not there yet, so don't be too hard on yourself. From time to time, we may stumble and fall. We all do, but our Father in heaven will not forsake us. God will lift us up with His strong arms of love.
Be patient with other believers, when they stumble and fall. God is still working on them too. "Brethren, if a man is overtaken in any trespass, you who are spiritual restore such a one in a spirit of gentleness, considering yourself lest you also be tempted" (Galatians 6:1). Judging other believers doesn't help. Just remember who we shall be, "we shall be like Him."