The short answer: Yes. (CCC 2041-2042)
And not only are we required to go, but it is considered a grave matter of sin if we do not go (and otherwise reasonably could have gone).
From the beginning, the Church has always seen this as the primary (and bare minimum) fulfillment of the 3rd commandment: Keep holy the sabbath day (the Christian Sabbath being The Lord’s Day).
Many will read the 3rd commandment out of context and in today’s present culture and interpret for themselves that it simply means to make sure and do holy things on Sunday. Not only does this not make a lot of sense, it is not the way that the apostles interpreted it either.
God commands us to be holy everyday – not just on the sabbath. And it would be a pretty useless commandment if it actually meant to just be extra holy on Sunday.
We are also to refrain from doing unnecessary work on Sunday, but not just so we can relax and play golf, lay by the pool or bake cookies. It is to free us up to fulfill another more important and sacred obligation.
In the full Christian sense, “keeping the sabbath holy” is to actually participate in the most fundamental of Christian celebrations – the mass.
“The Sunday Eucharist is the foundation and confirmation of all Christian practice. For this reason the faithful are obliged to participate in the Eucharist on days of obligation, unless excused for a serious reason (for example, illness, the care of infants) or dispensed by their own pastor. Those who deliberately fail in this obligation commit a grave sin.”
(FYI – Every Sunday is a “day of obligation”)
So it’s important. And this is not up for interpretation, as some Catholics might argue. If you are Catholic, you are obliged to go to mass every Sunday – not just Sundays where you wake up early enough, it’s convenient, or you are in town visiting mom and dad.
And there’s a special obligation for parents to take their kids and any other dependents under their care.
There’s no question that a lot of Catholics don’t attend mass as they should. I suppose it is partially because they are unaware that it’s a requirement, but I think the heart of the problem is that most Catholics take for granted what happens at the mass. I know I often do.
But then I think about what happens at each and every mass. And I realize that this is the most deliberately specific thing that Jesus gave Christians to do after he left (“Do this in memory of me”). And I contemplate that we truly, physically receive the body and blood of Christ – of God Himself – at every Mass. And I consider that communion with God is the ultimate goal of my life.
Then I can’t wait to go. Attending mass is not just an obligation, it’s a privilege! It’s a gift.
This is not a rule the Church makes for rules’ sake. It makes it for our sake. And it recognizes it as a grave sin because it is just that important to each one of our lives (i.e. really important).
“Except you eat the flesh of the Son of man, and drink his blood, you shall not have life in you.” – John 6:54
Ultimately, Mass should be one of (if not the) highlight of our week. We should look forward to it. We should want to go. And when we don’t, it’s a reminder that we need to work harder to more fully understand the reality of what happens at Mass. It’s human and natural to forget, get lazy, take it for granted, or become numb to it, but we have to continually work to overcome that trap. For we are being offered the greatest gift God has to offer – the source and summit of our Faith, Jesus Christ Himself.