The church I go to and love, Open Arms, has a motto based on Jesus’ summary of the Law & Prophets: “Connecting people to people and connecting people to God.”
Jesus spelt out the way of connecting people to God when He told Nicodemus that “You must be born again”. You can find an account of His conversation with Nicodemus if you read John’s gospel, chapter 3.
Open Arms seeks to connect people to people (people who are already connected to God) by being as culturally relevant, welcoming and interesting as possible. Ultimately the aim is to connect as many people to God as possible since He is the only way to eternal life or heaven (see John 14). Unless you are born again you cannot even see the kingdom of God, never mind enter it and live for ever.
So you must be born again.
There is a very good case for leaving it at that. If we all just spent our time bringing everyone we knew to the place where they were born again – or at least presented with that possibility – we would have spent our lives very profitably. This approach to life is called evangelistic and some people who meet God are called to it almost exclusively and everyone is called to it to at least some extent.
However the bible has a lot more to say about what it means to be a follower of Jesus after that initial, critical, connection has been made. If you have been born again God wants you to have two things that he talks a lot about in the bible: Communion with Him and fellowship with others who have been born again (i.e. with His Church). The Scriptures spend a lot of time dealing with this.
Communion and fellowship are eternal. Once you are born again and transferred from the kingdom of darkness into the kingdom of life, communion and fellowship is your eternal destiny. It is where God wants you to be now and forever.