Saul had proven himself to be, if not cowardly, then unsure, indecisive, and selfish. While he did have success defeating many enemies of Israel (1 Sam. 14:47-48) he didn't destroy the Philistine garrison in Gibeah as expected (10:5). Jonathan did that, which kicked off the war of chapters 13-14. Saul then didn't have the courage to wait for Samuel. It was Jonathan's courage and faith, shown in the first verses of chapter 14, that jump-started the victory. Saul's stupid and selfish command kept Israel from a complete victory, which Jonathan immediately recognized. Saul is shown to be a selfish man with a carnal viewpoint, and his lack of faith led nearly to cowardice, while Jonathan's strong faith brought deep courage.
Is it any wonder that after watching his father dither for at least 25 years Jonathan had a strong reaction upon meeting David? "And it came to pass, when he had made an end of speaking unto Saul, that the soul of Jonathan was knit with the soul of David, and Jonathan loved him as his own soul." (1 Sam. 18:1) David had just attacked a man well over nine feet tall, an experienced warrior from whom all else ran. David had no battle experience and was unarmored. David's confidence did not come from anything of this world. It was his faith in God that led him to charging at a giant. Jonathan saw this and seemed to think, "Finally, someone with whom I can share my faith."
Estimates of David's age when he killed Goliath range from 15-20 years old. He was called a youth by Saul and wasn't expected to fight, most likely making him under 20 as that was the minimum age of those able to go to war according to the Law (Num. 1:3). Meanwhile, Jonathan was old enough to fight in one of Saul's earliest wars and it had been 25 to 30 years since Saul had been anointed king. (Saul reined 40 years. David was 30 when he became king. So, Saul had been king 10 years when David was born.) Jonathan was likely 45-50 years old when he met David. So this friendship was more like a mentor-mentee relationship than bosom buddies or Best Friends Forever! (BFFs). A hint of this can be seen in how David approached Jonathan for advice when Saul first began to pursue David. (1 Sam. 20:1-3)
To all worldly viewpoints this friendship was counter-intuitive. Jonathan was mentoring the man who was to take his place as Israel's king! While Jonathan remained loyal to his father, he put his father's wishes behind him and squashed whatever ambitions he felt himself in his love for this youth who acted upon his faith.
This is something we should imitate in our friendships and loyalties. Earthly blood should not define our closest relationships. Similar earthly interests should not be the basis for our closest friendships. Our closest relationships and deepest friendships should be with those who share our faith. Our buddies are those who work with us in the Lord's Kingdom. Our BFFs are those who join us in attacking Satan, and we should be quick to mentor the younger, a la Jonathan (1 Sam. 23:15-18).
2 Cor. 6:14 "Be not unequally yoked with unbelievers . . ."
1 Pet. 1:22 ". . . love one another from the heart fervently"
Lucas Ward