What could the writer of Hebrews be referencing when he mentions the sacrifices of doing good and sharing what you have in verse 16? Doing good and sharing seems to be standard fare for followers of Christ and so many others too.

Goal is to instill Confidence that:
1. The Lord is my helper; I will not be afraid.
2. Christ is reliable as Thomas Oden describes in Classic Christianity
3. Jesus is the same yesterday, today, and tomorrow.
4. “The Christ in his own heart is weaker than the Christ in the word of his brother.” from Life Together by Dietrich Bonhoeffer

Sacrifice of solidarity instead of sympathy: Compassion.

Sacrifice of personal holiness: Character.

Sacrifice of being content and not loving money: Capacity.

Do not neglect to do good and to share what you have, for such sacrifices are pleasing to God. - Hebrews 13:16 NRSV