He has delivered us from the power of darkness and conveyed us into the kingdom of the Son of His love," Colossians 1:13 (NKJV)
When someone becomes a Christian they change kingdoms; we move from the devil's kingdom of darkness into God's kingdom of light. We can experience a sort of spiritual jet lag because we are coming into a place that is spiritually far removed from where we were living previously. We are accustomed to a certain way of thinking and acting and now those things are at odds with our new spiritual location.
When I fly to the USA from Germany or back to Germany from the USA one of the first things I do is change the time on my watch to the time it is at my new location. Then, when I have landed in my new location I keep my thoughts focused on where I am and not on where I was. Spiritually, once we become a Christian we need to change our way of life as soon as possible. We are not Christians because we follow some set of rules but God gave directions on the best way to live and by living a life that is in agreement with God's Word it is easier for us to quickly get acclimated in our new spiritual location.
Now that we have moved into our new spiritual location we need to focus our thoughts on where we are and not where we were. Too many Christian's minds are not renewed with God's Word and it leads them into trouble. By making some adjustments in our way of thinking we can easily make the most of our new life with God and minimize the difficulties we may face in our transition from the devil's kingdom of spiritual darkness into God's kingdom of spiritual light.