For I am confident of this very thing, that He who began a good work in you will perfect it until the day of Christ Jesus.
God will never stop working in your life to make you like Jesus!
Look at the verse again. The Apostle Paul is totally confident about this principle. When you think about it, it's obvious. After the massive investment God made at the cross to begin a new life for you, of course He will keep on working to bring it to maturity.
Although you will have some very powerful landmark experiences with God in your Christian life, you will never be at a point where you have ‘arrived', until the "day of Christ Jesus." That is, until you stand with Jesus in glory, you will never arrive at a fixed place in your spiritual life where you no longer need to grow and mature.
But God's emphasis to us today is on the positive side. Your spiritual growth is not only dependent on what you can produce. From the other side God is actively working in your life to pull you up towards Him. He wants to help you grow. And He will keep on helping you mature until the day you die. He works through people in your life, through your time in His word, through your circumstances, through your prayer times. Don't ignore the things that God wants to use in your life.