Living faith
God produces faith in us by His Holy Spirit through the specific means of Word and the sacraments. That faith, just like anything that is living, needs to be sustained and kept alive. Thankfully for us, the same Spirit that produces faith also sustains it.
Receiving our reward
We receive our due rewards in this life, and sometimes we receive what we don’t even deserve. But, every time we receive Christ through His Word and sacraments, we receive our eternal reward: life forever with Him.