If you were told that something was not optional of course you would feel that your freedom of choice or freedom of conscience was not respected. No one has the right to control another’s conscience. However, a fundamental tenet of Roman Catholicism is to control or compel the conscience; this is the primary reason why millions of Protestants died during Papal rule, because they dared stand for freedom of conscience. Do not be fooled when you hear of Pope Francis and the Roman Catholic Church advocating religious freedom or any other type of freedom, it is just a ploy to garner support and accomplish the church’s selfish ends. It should not be astonishing that in 2018, Roman Catholics still use threats and other fear tactics to force submission to Roman Catholic doctrines, principally that of attending Sunday Mass, which in the future will not only apply to Roman Catholics but it will extend to everyone as in the time of the Dark Ages. Missing the mass is considered a “grave sin” as will be shown in the following paragraphs. In fact, throughout the year, the Roman Catholic Church has what they term “Holy days of obligation,” wherein individuals are obliged to attend the Mass, one such day is Sunday.
“In a pastoral letter for the Solemnity of Corpus Christi, Archbishop Leo Cushley of St. Andrews & Edinburgh stressed the importance of the Sunday Mass obligation for Catholics.‘It is true that many people think of Sunday as just part of the weekend, a welcome break from the usual routine, and perhaps a day for family, or sporting activities,’ the UK archbishop said in the letter. ‘Naturally, it’s good to relax and make time for these things, but our culture has largely forgotten that Sunday is a weekly holiday because of its meaning as the Christian holy day,’ he continued. Cushley went on to emphasize the importance of attending Sunday Mass. He noted that missing Mass due to extraordinary circumstance, such as an illness, is acceptable, but under normal circumstances, ‘attending Mass on Sunday is a solemn and binding obligation.’
‘If we deliberately fail in this matter, it is a grave sin and we must go to confession before receiving communion again,’ he said...Cushley also highlighted the importance of the Eucharist, saying the Sacrifice of the Mass is a ‘foretaste of heaven’ that empowers ‘us to do real and lasting good in the world.’ Without the power of the Mass, we are not only cut off from the mystery of grace, but also from Christ and community, he said... ‘Coming to Mass only every other week, or occasionally, is not the same as being faithful to his New Covenant. Surely, we cannot treat Christ our Saviour as one option among others for us to shuffle at our convenience,’ he said. ‘I therefore urge you, brothers and sisters, to make the choice to attend Sunday Mass, to make it a priority, and to bring others with you.’”
The Archbishop is only echoing the words and sentiments of Pope Francis who made similar statements which are encapsulated in the following headline: “Pope Francis: It’s not enough just to ‘be good.’ You must go to Mass.” The article relates, “A Catholic cannot just do good deeds and miss Mass on Sunday, Pope Francis has said. It is the Eucharist that provides the spiritual nourishment Christians need to truly live out the Gospel in their everyday lives. ‘How can we respond to those who say that there is no need to go to Mass, not even on Sundays, because what is important is to live well, to love our neighbours?’ the Pope asked at his general audience. ‘It is true that the quality of the Christian life is measured by the capacity to love, but how can we practice the Gospel without drawing the necessary strength to do it, one Sunday after another, from the inexhaustible spring of the Eucharist?’ It is true that Catholics must go to Mass because it is the law of the Church, the Pope added, however this alone is not enough...Without the Eucharist, Christians ‘are condemned to be dominated by the fatigue of everyday life.’”
Consider the harrowing history of Roman Catholicism and how she dealt with those who remained away from the mass, as well as the blasphemous nature of the Eucharist and transubstantiation.
“At one time a whole family was brought before the inquisitors, charged with remaining away from mass and worshiping at home. On his examination as to their practices in secret the youngest son answered: ‘We fall on our knees, and pray that God may enlighten our minds and pardon our sins; we pray for our sovereign, that his reign may be prosperous and his life happy; we pray for our magistrates, that God may preserve them...’ Some of the judges were deeply moved, yet the father and one of his sons were condemned to the stake.” “The Scriptural ordinance of the Lord's Supper had been supplanted by the idolatrous sacrifice of the mass. Papal priests pretended, by their senseless mummery, to convert the simple bread and wine into the actual ‘body and blood of Christ...’ With blasphemous presumption, they openly claimed the power of creating God, the Creator of all things. Christians were required, on pain of death, to avow their faith in this horrible, Heaven-insulting heresy. Multitudes who refused were given to the flames.” 
History is repeating, as Pope Francis is advocating nations enforcing Sunday as a day of rest to combat climate change as well as to address poverty, as recorded in the Pope’s encyclical, Laudato Si: “Sunday, like the Jewish Sabbath, is meant to be a day which heals our relationships with God, with ourselves, with others and with the world…It [Sunday] protects human action from becoming empty activism; it [Sunday] also prevents that unfettered greed and sense of isolation which make us seek personal gain to the detriment of all else. The law of weekly rest forbade work on the seventh day…[See Ex 23:12]. Rest opens our eyes to the larger picture and gives us renewed sensitivity to the rights of others. And so the day of rest, centered on the Eucharist, sheds it light on the whole week, and motivates us to greater concern for nature and the poor.” He also stated that observing Sunday as a day of rest is not only for Roman Catholics, but for all: “Pope: No-Work Sundays Good, Not Just for Faithful…Maybe it's time to ask ourselves if working on Sundays is true freedom. He said that spending Sundays with family and friends is an ‘ethical choice’ for faithful and non-faithful alike.”
It bears repeating that the “obligation” of attending mass on Sunday and abstaining from work, shopping and other secular activities on Sundays will not only be urged upon Roman Catholics but will be imposed upon all “both small and great, rich and poor, free and bond” (Revelation 13:16) when the time comes that “Roman Catholic principles will be taken under the care and protection of the state.”
 White, Ellen. The Great Controversy (1911), page 240
 White, Ellen. The Great Controversy (1911), page 59
 White, Ellen, The Review and Herald (June 15, 1897)