David picked up smooth stones from the brook to slay his giant. God give us our own stones for slaying the giants that we face.
Stones to have ready:

Stone of Joy:
There's nothing more fulfilling to have than the joy of the Lord when the giants come out to fight us. When those giants show up, whether they be financial, health-related, or whatever the situation, we need to just stick that stone of joy in our sling and hurl it. It can help knock those giants flat.
"...for the joy of the LORD is your strength." Nehemiah 8:10

Stone of A Good Attitude:
Ever notice how we let things bother us when we've got a bad attitude? It may be a small giant that shows up, but when we've got a bad attitude, it can look as big as Goliath. If we throw the smooth stone of a good attitude the giant's way, it becomes a much smaller giant.
"If we live in the Spirit, let us also walk in the Spirit." Galatians 5:25

Stone of God's Word.
This smooth stone we need to carry around with us all the time. We need to have it hidden safely away in our hearts so that we can reach in and place it in our sling any time we need it. Recalling Scriptures when faced with our giants can make a big difference in the outcome of our battles.
"For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart." Hebrews 4:12

Stone of Wisdom..
Wisdom is a very powerful stone to use when facing your giants. The Bible is full of the wisdom we need in any situation we face, such as raising out kids, financial matters, personal relationships and just general everyday life situations.
"For wisdom is better than rubies; and all the things that may be desired are not to be compared to it." Proverbs 8:11

Stone of Gratefulness.
When we are counting our blessings, the giants that come to call don't have such a big impact on us. Grateful hearts give us a different perspective. The giants seem smaller and more surmountable.
"And let the peace of God rule in your hearts, to the which also ye are called in one body; and be ye thankful." Colossians 3:15

Stone of the Promises of God..
When the giants come out, call our name, and are just waiting to do battle with us, recalling the promises of God can send those giants running. So many promises are given to us to use for our strength. We are promised eternal life, sufficient grace, guidance, that God will never leave us, that He'll keep us from falling, and many others.
"Whereby are given unto us exceeding great and precious promises." 2 Peter 1:3

Stone of Prayer.
What a giant slayer prayer can be! It can bring such satisfaction when facing a trial or some type of roadblock in our lives. If we'd just get this stone out first and use it, our giants might not stick around so long.
"Be careful for nothing; but in every thing by prayer and supplication with thanksgiving let your requests be made known unto God." Philippians 4:6

Stone of Hope.
We have to remember that our hope is in the Lord. He already knows the outcome of our fights with our giants. It is Christ who we rest our hope in.
"Happy is he that hath the God of Jacob for his help, whose hope is in the LORD his God:" Psalm 146:5

Stone of the Strength of the Lord.
What power we have over our giants when we rely on God to take care of them for us. David faced Goliath with the strength of the Lord and it can zing the giants of our lives right in the middle of the forehead too.
"Then said David to the Philistine, Thou comest to me with a sword, and with a spear, and with a shield: but I come to thee in the name of the LORD of hosts, the God of the armies of Israel, whom thou hast defied. This day will the LORD deliver thee into mine hand; and I will smite thee, and take thine head from thee; and I will give the carcases of the host of the Philistines this day unto the fowls of the air, and to the wild beasts of the earth; that all the earth may know that there is a God in Israel. And all this assembly shall know that the LORD saveth not with sword and spear: for the battle is the Lord's, and he will give you into our hands." 1 Samuel 17:45-47

When giants come at us, we sometimes pick up those jagged rocks of anger, disappointment, worry, and frustration. We wind those things up in our sling and let them fly. We forget that God has already given us powerful weapons to destroy our giants with. Just one of these smooth stones can bring the biggest giant to his knees if we just think a little bit more before going to battle.

Do you have your stones ready to sling at your giants?