We have an adversary which is the devil, who is more terrible than the likes of Goliath but the good news is that we also have a God who would always give His children victory. The word of God says that Satan, as a roaring lion goes to and fro, look for whom he may devour and this was actually what Goliath did. Goliath roared at the Israelites and they were all afraid before him.
The Israelites on the other hand overcome their adversary through David the Lord anointed. Goliath came, cursing David by the name of his gods and David confronted Goliath by proclaiming the Almightiness of Jehovah Nissi.
The story in Exodus 17:8-16 also lets us know plainly that battles of life are above the physical. The children of Israel won the battle against the Amalekites as long as Moses’ hands were raised in prayers and worship to the Lord. When Moses’ hands became heavy, the Lord provide help through Aaron and Hur to hold his hands up while the battle was going on until the Amalekites were totally conquered. Moses returned all the glory of the triumph to the Lord by raising an altar and naming it “Jehovah Nissi” meaning the Lord our banner to acknowledge that God is the Banner over Israel.
We need the Almighty God to be the Banner over our lives if we are to win in the battles of life because we wrestle against flesh and blood. We must in this manner put on the whole armor of the Lord as we can't overcome the battles of life with our sense of physical weapons. When King Saul wanted to give a physical weapon to the young David, he rejected it in the light of the fact he knew the battle was the Lord’s. David went to the battleground in the name of the Lord with just a sling in his hands because the name of the Lord is a strong tower.
I advise you to take hold of the name of God as from this moment and you will overcome every challenge that comes against you. However, you must have a serious relationship with the Lord by obeying him and living holy.