For me, I think Luke 17:20-21 holds the key
"The kingdom of God does not come with your careful observation, nor will people say, 'Here it is,' or 'There it is,' because the kingdom of God is within you."
When you are born again, God sends His Holy Spirit to dwell on the inside of us. He makes us Sons and Heirs to His entire kingdom. In fact, we are co-heirs with Christ ( Romans 8:17 ), which means we have legal right to everything Jesus owns as His joint heir. Our inheritance depends on our position as a son of God. ( Romans 8:14-17, Galatians 4:6-7 ). We cannot lose this sonship or inheritance by what we do because it was a gift in the first place. In fact, the Holy Spirit is given to us as the deposit guaranteeing it. ( Ephesians 1:14 ).
The list of things Paul is talking about in Galatians 5 (Also I Corinthians 6:9-11, in which he says the same thing as Galatians 5:21) are characteristics of the unsaved, which will not inherited the Kingdom of God, because God does not dwell on the inside of them. Obviously these churches and the believers there struggled with these things so Paul simply reminded them that these things were uncharacteristic of who they were in Christ as children of God.
The remedy he gives in Galatians 5 is to walk after Spirit of God, who they were fashioned after in the first place ( Ephesians 4:24 ). If the things of the flesh are evident in our lives, then in the same way, the things of the Spirit are evident... love, joy, peace, patience, kindness, goodness and self control. These things are part of the kingdom living inside of us and part of our new nature and our inheritance as children of God. They already exist, God's placed them there, we simply have to release them.