What is the mark of true friendship?

1 Samuel 18:1-4After David had finished talking with Saul, he met Jonathan, the king’s son. There was an immediate bond between them, for Jonathan loved David. From that day on Saul kept David with him and wouldn’t let him return home. And Jonathan made a solemn pact with David, because he loved him as he loved himself. Jonathan sealed the pact by taking off his robe and giving it to David, together with his tunic, sword, bow, and belt.

Proverbs 17:17A friend is always loyal, and a brother is born to help in time of need.

Loyalty and commitment are the marks of true friendship. These traits bond friendships, despite changing circumstances.