Meaningful sacrifice

God does not require that we sacrifice animals, and other stuff, to please him, but he does require a sacrifice a praise and obedience.

Now, if we wish to offer further sacrifice, such as fasting, that's fine, but we must do so correctly. In Isaiah 58:3-5 (NLT), God highlights incorrect sacrifice,

Even while you fast,

you keep oppressing your workers.

What good is fasting

when you keep on fighting and quarreling?

This kind of fasting

will never get you anywhere with me.

...
Is this what you call fasting?

Do you really think this will please the LORD?

The rest of the chapter notes that, first and foremost, we must obey his commandments. And if we do (verse 11, NLT),

The LORD will guide you continually,

giving you water when you are dry

and restoring your strength.

So let's offer God our praise, and obey his commandments. Whatever spiritual exercises we do beyond that, let's not lose sight of our primary spiritual requirements.