Hi, Kevin —

Thanks for the question.

In the Mark's Gospel, Jesus tells us:

"The sabbath was made for man, and not man for the sabbath." (King James)
or
"The Sabbath was made to meet the needs of people, and not people to meet the requirements of the Sabbath." (Living Tradition)

The primary means of worship for any Christian is Catholic Christian worship.

We renew our covenant with the Lord every (Sunday and Saturday vigil) by attending and trying to actively participate in the "Mass", a word that, in Latin means "to be sent", because the Apostles were sent by Jesus.

Because all people are on various faith journeys, the Lord accepts the worship of anyone on Sunday. It's the good intent that counts, even if they only worship on Saturday or, for that matter, any other day of the week. I only consider it unusual in the sense that it deviates from our Lord's Scriptural wish.

Of course the divine authority Our Lord delegated to St. Peter in Matthew 16:13-20, was what changed the Sabbath from Saturday to Sunday, the Day of Our Lord's Resurrection. This is an Oral Tradition that is just as binding as the Written Tradition, understood correctly. (2 Thessalonians 2:15)

The Catechism tell us:

2000 Sanctifying grace is an habitual gift, a stable and supernatural disposition that perfects the soul itself to enable it to live with God, to act by his love. Habitual grace, the permanent disposition to live and act in keeping with God's call, is distinguished from actual graces which refer to God's interventions, whether at the beginning of conversion or in the course of the work of sanctification.

The sacraments of the Church give us sanctifying grace and, unlike actual grace, it is habitual grace. Over time, actual grace will draw a person toward the worship God intended for everyone: Sunday Mass.

You said:

• Also why do some people use God as an excuse to express their hatred?

Your asking a question that has nothing to do with issues of faith, morals, or the teachings of the Church but what the Church calls "theological opinion", which is never binding. It's just personal opinion. That said, I personally think it is a reflection of:

• a bad relationship some one has had with a father figure in their family, or
• a case of what one of my colleagues, Clayton Bower Jr. RIP said, is a case of Adolescent Atheism.
  

His defines it as follows:

Psychological or Adolescent Atheism is based, not so much on a true cognitive belief that there is no God, but is a reaction to overbearing religious parents and teachers just to get under their skin. Adolescent Atheism is a reaction to parental or adult demands. There is no real in-depth study of whether God exists, or not. The teenager or youth rebel just to identify themselves and their own identity. They are basically saying: "I'm not like this overbearing parent."

I hope this helps,

Mike