Reformed, I’d like to offer an analogy.
Think of a little child. When a child is given a gift, freely from his parents, does he always take perfect care of it? Sometimes children are very rough with their gifts. They may throw it around the house, break the pieces, loose the pieces if it was a gift that came with several parts. That doesn’t change the fact that the gift was given freely, and without their own merit.
And as with my own children, even if they mistreat the gifts I freely give them (both physical gifts and non visible gifts, such as my love for them), their treatment of those gifts does not effect my affection for them. However, when they do mistreat their gifts they have very real consequences for that choice.
If my son disobeys, he must spend time in time out. If he tells me a lie or responds to my love in an un-loving way, he must apologize. None of these acts change the love I have for my son, but each of these acts require action on his part to restore his relationship with me.
He can take the gift of mommy and daddy’s love and choose to respond in love, or he can run away, disobey, and refuse our gift. Just as in the story of the prodigal son, he chose to run from his father, the family he had been born into and the love that was offered for him. He ran and turned towards sin. But his father was willing to forgive and accept him when he turned from his ways and returned to his family.
How much more true is this of Christians? We may be born into the family of God through Baptism, but choose to reject that gift of grace by turning away. But if we are willing to return to God, to restore that relationship with him, and strive for a life of grace, we are responding appropriately to God’s free gift. It is not our own efforts that make us worthy of God’ s gift, but it is certainly our efforts and sinful natures that cause us to turn from that gift.
This is why the sacrament of reconcilliation is such a blessing from God! He KNEW from the beginning of time, that even though He would offer himself as salvation for the whole world, that we would fail and choose sin. So, through the sacrament, we have an opportunity to return to God, to choose his grace in faith, by responding to his love, with love. He is able to work through us, as instruments of his love, when we allow ourselves to strive for that state of grace.
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Salvation is truly offered to all mankind through Christ, our Lord. It is up to us, to choose participation in his saving grace, so that He can use us, transform us, to holiness. It is only in choosing to participate in the redemptive work of Christ, that we may serve and be pleasing to God :)
I wanted to add to the analogy

My son has a little brown stuffed puppy that he ALWAYS has to have in order to go to sleep. This puppy was a gift I gave him on his second birthday. He LOVES that puppy so much! He takes his little stuffed friend everywhere. They have played outside together, gone on car rides, rode in the wagon, played at the park. “Brown Puppy” has been covered in mud, dropped in puddles. He has been pulled and tugged so that his little puppy legs have started to loosen at the seams. Whenever my son gets his puppy dirty, or doesn’t handle him well, he comes to me.
I will take the puppy, and wash him. Sew the seams. Clean the stains. I make the puppy like new for him, and I always return this gift, out of love for my son, freely. No matter how much he has abused “brown puppy” I always restore his little friend to (almost new) condition and send them on their journey together again
Now…how much more can our Father, restore our relationship through Christ when we come to Him? When we “muddy” our relationship, or mistreat His free gift of grace? When I sew brown puppy back up, there is always a little trace of stitching that will never look like new. When I clean stains, sometimes a little bit will remain on his fur. But with our perfect, and loving father, our relationship is ALWAYS PERFECTLY restored! When we choose to turn towards him, his grace remains, unblemished and pure.