Everything else is life is so different. In the rest of our lives “we get what we pay for”. For this reason, the expectation that we must do something to merit eternal life with God is hard to shake.
Also most gifts we receive are small (at least relatively so). When we receive “free” stuff either it comes with some string attached or it is really worthless. This conditions us to not expect much from God’s grace.
But God’s grace is truly the exception. It is hard to believe, but here is an explanation and a way to think about God’s grace that might help:
When Christians speak of God’s grace it means this: that eternal life with God cannot be earned in any way, it is purely a gift. It can’t be earned because God’s standard for admission into Heaven based on personal merit is so high. It requires perfect sinlessness. This includes not being born with a nature that is inclined toward sin. So none of us had a chance, ever. Any extraordinary acts of love, sacrifice, or devotion do not compensate for sinfulness.
This does not make eternal life with God unattainable. It can be given to you. We can’t even add anything to merit a gift. When it comes to keeping God’s Law perfectly, Jesus had to do that as a human for all humans. When the Law requires damnation for all sinners, Jesus absorbed the judgment by His death and forsakenness on the cross. When there has to be a way to connect us to Jesus to receive these gifts, the Holy Spirit has to create the connection. We add nothing. Even our faith is the product of God.
Sometimes out of a false sense of responsibility or a proud sense of self-sufficiency, we twist the promise of eternal life through Jesus (the Gospel) to include our work in some way. The Galatians (from the New Testament book of the same name) believed that they were saved by Jesus and by being circumcised. Paul informs them that anyone who wants to add any aspect of keeping the Law must keep the whole Law themselves. In other words, if you won’t accept it as a pure gift, then you have to completely earn it.
People are constantly trying to add their works to God’s grace. You have to obey God. You have to “truly believe” God. You have to do other religious acts. But every addition makes salvation no longer a gift.
Say that you have a very wealthy friend. One day he or she presents you with a million dollar supercar for your birthday. You are overwhelmed by the gift and a little embarrassed. You can never respond in kind, so you unwisely offer your friend $100 to defray the cost. What have you done? You have dismissed the act of kindness and offered to buy a million dollar can for $100–an insult for sure.
This is why salvation must be a gift. The actual cost was for the Son of God to become a human (forever), for Jesus to keep God’s Law flawlessly, for Jesus to willingly endure mocking, punishment and crucifixion. And ultimately, for Jesus to be forsaken by His Father for our sins thus temporarily dividing the Trinity. What can we add that isn’t insulting?
Faith, praise, love, good deeds, lifelong dedication, et cetera are appropriate reactions to God’s gift, but they are not conditions or additions to God’s gift. God did this because He chose to love us. That’s all.
Since the gift of God that saves us was so costly, there isn’t a substitute. Makes sense, doesn’t it?
The gift of God saves all kinds of people. Some are decent people but still sinners. Others are monsters who come around with God’s help. The dependency on the gift of God, also leaves out all kinds of people. Relatively good, very religious, also a quite a few hardened sinners will reject the one thing that could save them. Don’t be that person.