But we wait for what God has promised: new heavens and a new earth, where righteousness will be at home.—2 Peter 3:13
VerseSource
Here we see that we have a future hope and glory. The hope of going to be with Christ in Heaven. So, Christianity is not a waste of time. We all have a future hope. Stay focused, live for Jesus no matter how many times you may have fallen.
Yes , Christianity is truly not a waste of time but practicing Christianity is not where it ends as it can't lead us to heaven. What will lead us to heaven is accepting Jesus as our Lord and savior and abiding by his commandments.
I remain @catoranking