Therefore let that abide in you which you heard from the beginning.
If what you heard from the beginning abides in you,
you also will abide in the Son and in the Father.
And this is the promise that He has promised us – eternal life.
1 John 2:24-25

Follow with all your heart that faith and that teaching which you have received from the apostles
at the beginning of the church,
for only this will make you partakers of divine grace…
John adds [verse 25] as if to answer those who want to know what point there is in following Christ.
What are we going to get out of it?
The answer is that we have been promised eternal life.
Bede, On 1 John