Psalm 50:16-17 (ESV)
But to the wicked God says:
“What right have you to recite my statutes
or take my covenant on your lips?
 For you hate discipline,
and you cast my words behind you.
Worship is a privilege. It is not a right. Of course in the political world of day to day affairs the right to worship is sacrosanct, as it should be. Human beings, political leaders, laws of men, simply should not have the ability to tell people who they can worship. It is a field outside their purview. They are called, in part, to enable all its citizens to be able to worship as they see fit.
There are limits on this, of course and that is right as well. No one, under the guise of religion, should be allowed to violate the universal sanctions against murder, stealing, adultery, child abuse, etc. So the political right of worship of what a person considers God, is to be defended by the powers that be. Governments are instituted by the one true God for the rewarding of the right and the punishment of the wrong (Romans 7:1-6).
And the principle of evangelism/proselytization should be permitted in the proper avenues of society. It is a Christian principle that it is the heart that needs to be changed before there can be genuine conversion to the Lord Jesus Christ, and that cannot be legislated by law. But it should be permitted to make the attempt or else people will not be making their religious choices voluntarily and they will not be allowed to forsake religion according to the dictates of their consciences. We see people all over the world being refused the right to worship as they desire. Most of the time it happens to Christians who want to worship Jesus Christ. Only God can change the heart and no legislation should try to interfere in the process. When laws are put in place that prohibit people from freely choosing to worship whom they choose or freely recant a belief, then you have a very weak religious and political power structure. And you will have horrifying cruelty.
All of that being said it also needs to be said that God does not give people the right to worship whoever they want. Freedom of religion in the political realm does not transfer to God in the religious realm. On the vertical level no one has the innate right to approach God as he or she determines. Put bluntly, no one has the right to come into the presence of God as he or she chooses. It is by invitation only.
The people being addressed in Psalm 50:16 assumed that the qualification for worship was to be Jewish; to be part of the covenant community of Israel. They misread the invitation. They thought that their genetics trumped their behaviour. So they freely, and without conscience behaved in the manner described in verses 17-20 thinking that they could waltz into the place of worship, with no repentance, and claim membership in the covenant of Abraham. And they are rejected. God tells them they have no right to be there.
Who has a right to come into our churches and join with us on a Sunday morning? Entrance is freely available, on a human level, for everyone. But make no mistake. The reason all are invited to enter the building is because they are are first of all invited to repent and believe. They may come and sing and give and experience blessing. But God will still come to them and ask “What right have you to recite my statutes or take my covenant upon your lips?”
Worship is not a right. It is a privilege. There is only one way that you will ever have the right to worship God. And that is through the blood of Jesus Christ. He grants the right to worship. Worship is a gift of grace and if you have not come to Jesus, you do not have the right that such grace grants. But you can.
There is only one way to God and that is through His Son. The governing authorities may protect your right to worship wrongly. But God does not. You can only get to Him through Jesus. And He is there for you and for all who will trust Him and all He did to win people to become real worshippers of the One True God.