How will the next generation know about God? Only if we tell them. See what the psalmist says in Psalm 102.
This will be written for the generation to come, That a people yet to be created may praise the Lord .
Psalms 102:18 NASB
The psalmist is encouraging people to write down their witness for God. This way, others who have not yet been born, will be able to read about how God has impacted us and moved in our lives. Do we leave a testimony behind? Would others who studied our life 100 years from now know what we believed and why? Take a look at all the things you write today and social media posts. Are they leaving the legacy of a follower of Jesus Christ?