For Christians, the question of how we can be saved has too often been framed as a future question: how can I know I’m going to heaven when I die? But the Bible just doesn’t talk enough about going to heaven when we die for us to justify making that the baseline of our assurance of salvation.
Instead, the Bible talks about our assurance in terms of what God has done in the past and is now doing in the future; namely, he has become a human being in space and time so that he can – in the middle of human history and on the planet earth – die the death we should have died and rise from the dead to take away the barrier between us and God, and that he gives us this salvation in concrete, objective ways.
These concrete applications of his salvation are his word, which regardless of how we feel announces to us that he loves us for the sake of his son, Jesus Christ, and his sacraments, which are physical, objective promises of salvation to us. I might sometimes doubt, I might sometimes not understand the Bible like I should, I might sometimes do things that are sinful, but what never changes is that God’s word announces my salvation and my baptism into Jesus really happened.