"Lord, increase our faith!" was the request of the disciples in Luke 17. How does that happen? A look at the full context of this request (vs. 1-19) will show that there are at least three things God asks of us in order to grow our faith.
1. Use What you have (to do what you should)
It’s not the size of our faith that is most important, but the source on whom it is fixed. Even if we have just a little, it is powerful when placed in the solid character of God. Take the faith you have been given by God and simply start obeying him in the smallest areas. Look at what he has given you, and use it in faith to bless others and glorify his name. That’s how faith grows -- when we simply act on what we already know or take what we already have and put action to it. Being faithful in what we already have or to what we already know opens the door for greater faithfulness in larger things later.
In fact, a synonymous phrase for increasing faith is quicker obedience. Let me illustrate. Two men both have to jump just a foot or two off a ledge and grab hold of a branch over a large canyon, then stand up on the limb below them. What will affect their readiness to jump the most? Not who they are, but what the tree is like. Little tree? Slow jump (if at all!) Big tree with firm roots? Quicker jump? You get the point, right? Even a little confidence in the tree can lead to a big jump. And for sure, delay indicates doubt. After all, it’s one thing to analyze; it’s another to be paralyzed. The common factor to both is the state of the tree.
Remember Peter? He was the first one out of the boat, indicating his faith in Jesus was strong. When did he start to sink? When he took his eyes off the source of his faith and onto the size of the waves. Don’t knock him for sinking. Applaud him for such strong faith that obeyed so quickly and showed he trusted Jesus without reservation.
Gideon did this, too, when he simply used what he had to obey what he knew. He took the ten men and cut down the idol his father had erected. While it was important, it didn’t require things out of his immediate reach. He started with what he had where he was. It was small faith that had a big impact.