"Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.
Sometimes we have the attitude that we're doing God a favor by listening to him... that he somehow needs us to believe in him or that we can use our obedience as leverage or as a basis for making bargains with him. And God definitely wants us to live the gospel, but he wants it for *our* sake, not his. When we try to use our obedience as a barganing chip, it's kind of like a teenager saying to his or her parents "if you really loved me you'd let me do whatever I want." That kind of emotional blackmail might work sometimes on fallible Earthly parents, but it doesn't work on God.
As Peter says in these verses, the gospel is a gift and a promise. It's the hope and the light that God blesses us with to counteract the darkness and bleakness we so often encounter in life. It's a way that he can help us find happiness and true purpose. Today, let's remember that God loves us and wants to see us learn and grow and become competent adults, spiritually, even if we already are physically. Let's stop thinking that getting our way is the ultimate goal in life, and realize that God, being all-knowing and stuff, might actually have a better plan for us. Let's accept his gift, and his promise, and do what it takes to choose that better way.