For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. Ephesians 2:8-9 (ESV)
One of the Bible’s greatest truths is that God offers us our salvation as a free gift. It isn’t something we can buy, and it isn't something we can earn by doing good works.
The Bible also tells us two important truths about God’s gift of salvation. First, it tells us that it is a costly gift. Think of it this way: If you want to express your love for someone by giving them a very fine gift, what do you do? First, you go to the store and buy it. And the finer the gift, the more it costs you. To your friend or loved one, it’s a free gift, but it wasn’t free on your part.
The same is true with God’s gift of salvation. To us it’s free, but it cost God the life of His Son. The reason is because on the cross Jesus Christ became the final sacrifice for our sins. He paid for our salvation with His blood.
The Bible also tells us a second truth: Like any other gift, God’s gift of salvation doesn’t become ours until we accept it. Just as we can refuse the gift someone offers us, we can also refuse God’s gift of salvation. But for those of us who believe, it is the best gift of all.
“Salvation is not a reward for the righteous, it is a gift for the guilty.”