Scripture
And he became more and more powerful because the Lord God Almighty was with him.
Observation
The elders of the northern tribes meet with David and appoint him as their king, effectively reuniting the country.
David and his men go to Jerusalem, capturing the city from the Jebusites. The Jebusites were complacent in their stronghold, believing that it was virtually impregnable.
David takes up residence in the city building it up and enjoying the favour of God.
Application
David was successful because his heart was right with God and God was favourable to him.
This doesn't mean that he was free from battles or that there wan no cost to his mission. It does mean that as long as he looked to God he could be confident in the Lord's blessing.
David was by no means perfect, but he was faithful to God.
When the Lord calls us to follow Him, He gives us the ability to live in that calling. He gives us the Holy Spirit to enable us to do all that He has called us to do,
Prayer
Thank you Father for the knowledge that you will carry me as long as I seek to do your will. Amen.