In my interpretation this is what he's telling the church:
I'm pushing through the obstacles towards my prize which is heaven, where I want to be, & Christ has made a place for me. All of us who understand the true purpose of our walk need to look at things in this perspective, be heaven minded! And if any of you lose focus God can get you back on track. Let us continue to keep up the pace and live worthy of the life we are called to & not fall back into evil. What we have already achieved live up to that as you press on and press forward. See my example, live that way too and keep your eyes on others that live right. It breaks my heart to see those who live and direct discord with God those who do not make Him known him or reverence his sacrifice, they don't take hold of the power that it has, they live as if what Christ did means nothing to them. Sadly, the Bible says that they are enemies of God. (An enemy is someone who is actively opposed to someone or something.)
Their end will be ruins, their focus is on things that will waste away. But we have set our hearts on heaven, we have made that our home, our place of belonging, our final destination, we have been stamped with the citizenship of heaven. We believe that our Savior is coming back for us and we wait for his return. We believe that God has given him the power to rescue us from our sinful nature and transform us to heavenly glory. Amen!