God's covenant with David is fulfilled through Jesus. God will always do what He says. All the promises of God are fulfilled in Jesus.
Contention comes when two different world beliefs collide. Jesus is the way, the truth, and the life. We must fight for that truth in these last days.
God's work is hindered by unbelief. A person's life is not changed until they believe on Jesus. Are you a "believer?"
Do you have a well of water springing up into everlasting life in you? Jesus will give you eternal life if you will believe on Him.