David and Jonathan shared many similarities, both were:
young and capable,
military heroes,
had strong faith in God, and
had claims to Israel's throne (each had a reason he could become king).
Jonathan's true character showed when he recognized and supported God's choice of David as the next king of Israel (see 1 Samuel 18:3–4; 20:12–17).
Jonathan loved him as himself: See 1 Samuel 20:17; 2 Samuel 1:26. Others in this chapter are also said to love David:
all Israel and Judah (1 Samuel 18:16),
Saul’s daughter Michal (1 Samuel 18:20), and
Saul’s servants (1 Samuel 18:22).
Some modern interpreters suggest a romantic relationship between David and Jonathan. However, the biblical text describes their relationship as a deep and loyal friendship.