1. It means the gospel is of God
We never would have made this up. The messages of religion tell you that by you being better or brighter you will attain salvation, and so you can retain your self-righteousness, take the credit and get the glory. The gospel strips all that from us. When we accept the hard truth of our sinfulness, we see that it fits reality - everyone of us is conscious of our sinfulness, it comes naturally to us. Children don't have to be taught how to selfish or deceitful. The message of the gospel accounts for this. And the idea that a perfect being could be bribed to forgive our wrong-doing on the basis of some good things we have done is unjust and ridiculous. The gospel says God is absolutely righteous and completely perfect and so we can never be accepted by Him based on the lives we have lived.
2. It means salvation is by grace
We never could earn God's favour, so salvation is offered to us by pure, rich grace. This means that you can have it right now. You don't have to become something you aren't; you just have to admit what you are - a sinner, and receive salvation as a gift you don't deserve and can't earn.
You don't have to impress God. As Tim Keller said, "All you need is need; all you need is nothing."
Jonathan Edwards put the same truth this way, "You contribute nothing to your salvation except the sin that made it necessary."
God has paid the cost and done the work through Christ. You aren't worthy of salvation but you are welcome to it. It's there for the taking; it's yours for the asking.
3. It means security is guaranteed
If we could never be good enough to win God's acceptance, we can never be bad enough to lose it. It's not my faithfulness that guarantees my safe arrival in heaven; it's His. It's not the strength of my faith that secures me; it's the strength of the one I put my faith in.
The biblical teaching of the sinfulness of man is hard to swallow - it's bitter in the mouth, but it when you swallow it, it's actually pretty sweet - the gospel is of God, salvation is by grace and security is guaranteed.
