If you stop believing and lose your salvation as a result, then the life you received wasn't eternal...it was only temporary.
See Ephesians 1:13-14, 2 Corinthians 1:22, 2 Corinthians 5:5.
God gives the seal of the Holy Spirit to those who believe.
Therefore, because of his abiding influence, those who have this seal will not fail to keep His word.
It's a seal of a guarantee to receive something at the end.
And it will be received IF the conditions have been met.
Like when you buy a house.
You receive a seal of guarantee that one day that house will be yours.
IF you make mortgage payments every month.
Anyway, the seal meant baptism.
The seal of baptism.
See JBF, I don't care if YOU believe what you believe.
I know you're a nice and mature Christian and will not leave the side of God and will be saved forever.
But there are new Christians out there that don't really understand things well.
I just hope they all go to a good church so this could be taught to them.
If faith is the instrument used to save us......
then NOT having faith will be what UNSAVES us.
Check out John 3:16
It's always in present tense.
EVERYTHING Jesus says is in present tense.
This should say something to you.