I don't think wearing a mask is equivalent to being unselfish. Neither is refraining from singing in church or maintaining proper social distancing rules.
Let me say this another way.
Good actions don't always come from a good heart. Not everyone who obeys government ordinances regarding COVID-19 does so out of love for God and love for others.
People are motivated to obey the rules for all sorts of reasons.
They do it to avoid guilt.
They do it to be appreciated.
They do it to be seen as good.
They do it so others will think well of them.
They do it to maintain their illusion of perfection.
They do it out of fear of displeasing God.
They do it because everyone else is doing it.
They do it to feel good about themselves.
They do it out of fear of dying.
They do it out of fear of the future.
They do it so their spouse won't pester them.
They do it so as not to rock the boat.
Or they do it because they just find masks terribly comfortable.
The fact of the matter is, we can't see what's inside others' hearts. One person might obey while secretly feeling God now owes him something. Another disobeys because he knows he cannot hide the rebel in his heart. The compliant individual is like the brother to the prodigal. The rebel is like the prodigal. From appearances, the compliant seemed less selfish. The rebel seemed totally selfish. But which one chose the right way? The one who repented. And which one needed to repent? Both.
Let me start from another point and maybe that'll make things clearer.
No one is good but God. No one loves God with all their heart, soul, and mind. No one loves their neighbor as themselves. No one acts from an unselfish heart. It's impossible.
However, God asks that we do just that. And I think it's a good idea to try because it's only through trying our darndest that we realize, we can't.
When we try to submit to the governing authorities (a good thing to do) by wearing masks and quarantining and temporarily not singing in church, most of us will probably discover that we have very little love in our hearts for those who don't do likewise. In fact, we feel quite angry at those people who are not keeping the rules as rigidly as we do and who accuse us of being afraid. We might discover that we actually only love those who behave according to our standards and treat us with respect.
I realize, this is not true of everyone. Those moved by the Holy Spirit will find love in their hearts even for those who point in their faces and call them rule-keeping, gullible cowards. Those lead by the Spirit neither feel the need to justify themselves or defend their reputation. They have fallen upon the Lord Jesus Christ for the assurance of their own goodness, for their security for the future, and for the power to influence others through love.
So the question for the Christian is not do we choose to love others or courageously fight for our freedoms.
The question is do we deceive ourselves into thinking we are good because of our seemingly unselfish or seemingly courageous choices, or do we recognize the many ways we fall short no matter how hard we try, repent of our self-centeredness, and ask God to do it for us?
"Just as surely as God desires to lead us to a knowledge of genuine Christian fellowship, so surely must we be overwhelmed by a great general disillusionment with others, with Christians in general, and, if we are fortunate, with ourselves."
Bonhoeffer, Dietrich. (2012) . Life Together. "Not an Ideal But a Divine Reality." [Kindle] Loc 144-165