His strength ...

... assures me that God has provided me with every blessing in abundance. By His grace, I have everything I need (2 Corinthians 9:8).

The apostle Paul was not saying that we have enough grace to do anything we want to do. God does not offer us a blank check. No, Paul was giving us the assurance that we have enough grace to do whatever God has called us to do ...

God uses us to do His work
If we will just obey;
He freely gives His love and power
To serve Him every day.

From Our Daily Bread.