Assurance of Salvation

I was talking with someone today about faith in God, Jesus and salvation and I was reminded of just how important it is to be well grounded in our assurance of salvation and that once God has saved us that no one or no thing can "unsave" us.

The following is what God has to say on the topic:

John 10:28-29 (NIV)
I give them eternal life, and they shall never perish; no one can snatch them out of my hand. My Father, who has given them to me, is greater than all; no one can snatch them out of my Father's hand.