Confident Living

I Samuel 17:33
‘And David said, “The LORD who delivered me from the paw of the lion and from the paw of the bear, He will deliver me from the hand of this Philistine.” And Saul said to David, “Go, and may the LORD be with you.”’

David is giving his personal history as to why he is confident in the Lord's ability to deliver. Much doubt could have been haunting him. One such doubt is "These examples were involving sheep. This time it's a professional soldier. Also an entire nation's freedom is at stake. Am I sure I heard right?" David's faith wasn't faltering. He was confident. A few verses earlier, we heard of how David's brother was trying to shame him into silence. David responded, then ignored him. 
The Lord works with each of us. We all could look back and see the Lord's hand in deliverance. David was a prophet, we are not. Sometimes the things we pray for don't work out as hoped. The verse in I Corinthians 13 comes to mind, here on earth, "we see through a glass dimly". Our vision isn't perfect. we can get things wrong.    
So, what are we to do? Galatians 6:9 is helpful, "Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up." We are to continue in praying for things we believe to be (or hope to be) God's will. He gives us desires and we adopt His ways. We are to pray with confidence and faith towards those ends.
Jesus says in Mark 11:24, "Therefore I say to you, all things for which you pray and ask, believe that you have received them, and they will be granted you." The Lord wants us to pray in faith. This is an area where we grow. It takes practice. Sometimes our prayers don't get answered the way we had hoped. We aren't to grow weary. Continue on with this practice. 
As new believers, we made many errors. As we mature our course corrections are smaller and fewer; more like fine tuning. 
Part of this practice is tending to our hearts and minds. There are many places that will provide doubts. Don't go there. Colossians 3:1 says, "Set your minds on things above, not on earthly things." David didn't entertain doubts. Part of the process of praying for things is to keep watch over our hearts. Galatians 5 details the fruit of the Spirit, love, joy peace, patience, kindness, goodness, faithfulness and self control. This fruit is what we are to be full of. Sometimes when we pursue things in prayer, competitive feelings of anger and punishment arise. We need to adjust things, as those aren't of God. That doesn't mean we abandon those aims, but to pull back to remain in God's character. 
In a nutshell, this practice is part of the Lord's prayer, "Thy kingdom come, Thy will be done". As we grow in Christ, we learn of Him, that He is good and His ways are the best. We adopt these and His goals. Not so much what we do, but how we do it. In love. He puts His heart in us. 
Lord, thank You for this wonderful life in Christ. You allow us to partner with You. Help us to pursue You and Your ways. Help us to apply faith in all we do.