Why do you think that getting with other people will make you holy? Only God can make you holy. Yet someone will decide they want to be closer to God and next thing you know, they are going to church. That sort of approach will only make you “holier than thou.”
The Pharisees thought that human relationships could make you holy. They thought that everyone who hung with them was holy. Everyone else was not. It was a game of human associations that had nothing to with God…except in name. It’s a game people are still playing today.
If you would be holy, spend time with God. Think about Him. Do things for Him. Listen to Him. Do what He says but don’t brag about it. Ask Him to help you understand what being holy is like. He is holy, and associating constantly with Him is the only thing that can make you holy. In fact, you already are holy by virtue of His eternally-committed relationship to you. You just need to bring your thinking and behavior more in line with His reality.