A promise is a promise. We have all made promises of one kind or another, and maybe when we look back we realise that we have failed to keep them. We should feel ashamed! It is better not to make promises than to make them and break them.
The people involved in the incident in Joshua 2:14 were the three spies sent out by Joshua. Rahab was a woman from Jericho. They made promises. The spies said they would save Rahab and her family when Jericho was attacked, and Rahab promised to protect the spies and let them get safely away. As it turned out, all of them kept their promises, with a very good result.
The Bible is full of God's promises. He made many promises to Joshua and the people of Israel, and Joshua said near the end of his life, "You know... that not one word has failed of all the good things that the Lord your God promised concerning you. All have come to pass..." (Joshua 23:14)
Paul the Apostle said about the Gospel, "This is the life God promised long ago — and he doesn't break promises." (Titus 1:2, The Message) God never lies; with him a promise is a promise! Remember that when you promise to do something. As Jesus said, "Don't say anything you don't mean." (Matthew 5:33, The Message)
Dear Lord, please help me to be a trustworthy person who does what I have promised. Amen.