Lesson
Worshipping God and obeying the commandment of man is not suppose to be, it's against the commandment of God and your worship is in vain.
Paul became the member of the church of God that he persecuted and the first thing God commanded Paul to do is baptism.
Those who receive the word of God were Baptised, the former act of joining the church of God is to receive the word of God then be baptised. If there's no need to join the church, then God won't build the church, it's build for man to join.
Those that didn't hear the word of God before they die might be save, those who didn't know the Bible, died before the Bible was printed might be save but if you hear the word of God and you didn't obey it, you might not be saved.
If you know the doctrine, join the church, if you know the doctrine and you didn't join, you still stopping people from joining, you are an anti Christ.
Lesson
Whoever think he belong to God need to act the way God commanded man to act, he don't have to follow the commandment of man because man is suppose to be under the commandment of God, and if you are worshipping man and you are worshipping God, that kind of worship can't be a genuine one, you have to be plain, follow who you want to follow, you can't eat from two tables, you have to choose God and follow His commandments or choose the devil and follow the commandment of the devil.
To join the church of God, the first thing you need to do is to be baptised, that is the first thing that God commanded Apostle Paul to do when Paul was first called to the church of God and Paul did it, apart from that, Lord Jesus Christ is the first example of Baptism, He made John the Baptist Baptise Him, not because He didn't clean or has committed so much sin like Apostle Paul, but it's because He want to lay good example for us to follow.
Jesus Christ was Baptised, then the main one we read is Apostle Paul's baptism and the Apostles made sure that the early Christians are baptised before they join the church of God, so the former act of joining the church of God is to listen to the word of God and then be baptised.
The Law of God has to be followed, if you can hear the preaching and you didn't make use of it until you die, then you may be punished, it's only those that are already dead before the preaching come to existence and did good in their life time can be saved on the last day.