"For my house shall be called a house of prayer for all peoples." (Isaiah 56:7)
When Jesus turned over the money changers' tables in the temple court, he was upset that they were take up space reserved for Gentiles. You see, there was a distinction between Jews and Gentiles (non-Jews). The family of Abraham was free to come into the inner court to worship God as his chosen people (not the inner, inner court...that was for the priests). God-fearers (as foreigners were called) were free to worship God in the outer court. But there was no room for them because of the stalls of the money changers and the sellers of wares.
While we may not have a division between where believers and unbelievers can sit in the sanctuary, there have certainly been plenty of ways we have excluded them from the presence of God. Some churches have required certain dress codes, turning people away because they weren't wearing the right things. More have turned away people who weren't sufficiently moral. Still more have been turned away because of the style of music, or because the language of church (Christian-ese, as it's been called) is inaccessible and confusing.
But God wants all peoples to come and worship him, to be formed into the people of God. And since the advent of Jesus, there is no inner and outer court separating us. "For he himself is our peace who has made us both one and has broken down in his flesh the dividing wall of hostility" (Ephesians 2:14).
So the question for us is, what barriers are we placing before the unbelievers that are not the gospel, that keep them out of the worship space of God? How are we keeping out those whom God has invited in? If we're praying for their salvation, it's best we remove as many obstacles to the gospel as we can. The gospel is challenging enough, isn't it?
Who are you praying for?