To endgame for every Christian is to be like Jesus. God said the He had planned to shape us to the image of His Son. The Bible term for this result is being His disciple. A disciple by definition is one who follows or imitates another, as Jesus disciples we are simply following His directive for life and doing whatever He would do.
The avenue to effective discipleship is found in these few verses.
In verse 28 we are told that God is involved in everything in our lives. He is able to make any event in my life work to my advantage and benefit. Some people believe that God keeps His children from sickness and poverty, but I believe that God can use even season of sickness and poverty to work to my benefit. Each of these cause me to become more dependent upon Him. I become more like Jesus as I become more dependent upon His strength (Though he was rich he became poor).
In the next two verses 29-30 we know that God has always had a plan for us. God knew us before we were born and He sought after us before we were saved. His goal is to take this measure of clay and mold it into something that resembles His Son.
If you are struggling to become more like Jesus it may be because you have not acknowledged that our God is in charge of all things and he has purposed that you will come out of this life to be like Jesus. You may let Him down, but He cannot and will not fail to present you faultless in heaven some day.