Get on board

There are different metaphors for the church. Some Biblical and some traditional. One traditional metaphor is a passenger ship. This may go back to viewing Noah's ark as a symbol for the church. 

Let's play along with that metaphor. A passenger ship is not an end in itself, but a means to an end. It has a destination. In the lifetime of a passenger ship, it repeatedly undergoes a complete turnover of passengers and crew. As a passenger ship goes from one port of call to another, some passengers disembark while new passengers come on board. That's like Christians who go to heaven when they die, while the church takes on new members. 

Some people are born into the church because they are born to church members. Others join a church as adults. By the same token, babies are sometimes born aboard a passenger ship. Conversely, some passengers die on board. They never make their destination–like nominal Christians. Some passengers commit suicide by jumping overboard, like apostates. Some ships sink when they collide with a submerged coral reef, like denominations overrun by heresy. Some ships weather storms, like persecution. 

In church attendance, there were passengers who precede us, as well as passengers who succeed us. We passengers on a transgenerational ship where some passengers are on the way out while others are on the way in. The faithful will leave the church behind when they die. It served its purpose. They made it to safe harbor.