Romans 15:20–21: And thus I make it my ambition to preach the gospel, not where Christ has already been named, lest I build on someone else’s foundation, but as it is written, “Those who have never been told of Him will see, and those who have never heard will understand.”
Romans 10:13–14: For “everyone who calls on the name of the Lord will be saved.” How then will they call on Him in whom they have not believed? And how are they to believe in Him of whom they have never heard? And how are they to hear without someone preaching?
So he's spreading religion by being an example of what he believes, not by forcing it on others. This is the way it should be done. But yes, the Bible clearly says you should promote it and you are clearly against religion since you deny someone the ability to do so even while not forcing anyone to join.