1 Samuel 14

I was so impressed with Jonathan and his armor bearer's great faith and courage.  Seeing that the Israelites were having trouble defeating the Philistines, -

"...Jonathan the son of Saul said unto the young man that bare his armour, Come, and let us go over to the Philistines' garrison, that is on the other side."  (Old Testament | 1 Samuel 14:1)

Upon sneaking to the other side -

"...Jonathan said to the young man that bare his armour, Come, and let us go over unto the garrison of these uncircumcised: it may be that the LORD will work for us: for there is no restraint to the LORD to save by many or by few.
7 And his armourbearer said unto him, Do all that is in thine heart: turn thee; behold, I am with thee according to thy heart.
8 Then said Jonathan, Behold, we will pass over unto these men, and we will discover ourselves unto them.
9 If they say thus unto us, Tarry until we come to you; then we will stand still in our place, and will not go up unto them.
10 But if they say thus, Come up unto us; then we will go up: for the LORD hath delivered them into our hand: and this shall be a sign unto us."  (Old Testament | 1 Samuel 14:6 - 10)

Their faith was so great in the Lord the their numbers did not matter "for there is no restraint to the LORD to save by many or by few."  And the sign that the Lord would deliver them was that after being discovered, if the Philistines challenged them to "come up unto us", they would find success.  And sure enough -

"...the garrison answered Jonathan and his armourbearer, and said, Come up to us, and we will shew you a thing. And Jonathan said unto his armourbearer, Come up after me: for the LORD hath delivered them into the hand of Israel.
13 And Jonathan climbed up upon his hands and upon his feet, and his armourbearer after him: and they fell before Jonathan; and his armourbearer slew after him.
14 And that first slaughter, which Jonathan and his armourbearer made, was about twenty men, within as it were an half acre of land, which a yoke of oxen might plow.
15 And there was trembling in the host, in the field, and among all the people: the garrison, and the spoilers, they also trembled, and the earth quaked: so it was a very great trembling."  (Old Testament | 1 Samuel 14:12 - 15)

And also as sign the Lord was with them, the Lord caused and earthquake.  These two men seemed to have much the same faith and righteousness as the sons of Helaman.