The Catechism in Questions & Answers

738. What is the relationship between sacrifice and blessing?

Basically, human beings can only bring sacrifices because God has already blessed them beforehand. These sacrifices are therefore an expression of gratitude for that which they have received.
In the case of any sacrifice, the attitude of heart is the deciding factor. If the sacrifice is made willingly out of thankfulness and love, blessing will be associated with it. This can be experienced in earthly life, for example in the form of natural wellbeing. However, blessing is primarily of a spiritual nature, which includes the imparting of divine salvation out of the merit of Christ (cf. Ephesians 1: 3-7).

“He who sows sparingly will also reap sparingly, and he who sows bountifully will also reap bountifully. So let each one give as he purposes in his heart, not grudgingly or of necessity; for God loves a cheerful giver. And God is able to make all grace abound toward you, that you, always having all sufficiency in all things, may have an abundance for every good work.”
2 Corinthians 9: 6-8