Blackmail is when someone is coerced into making a payment or doing something under threat of physical punishment. (Okay, so far it seems to fit.) But what is usually understood with blackmail is that the required payment or action is unnatural to the blackmailed party; such action or payment would generally be considered against their will or at least against their best interests. And this is where the analogy falls apart.
As God is perfect in His goodness and only wills that which is good, when we act against the will of God we are choosing an action that is at most, less than the highest good, and quite possibly, disastrous and destructive. We do not follow God merely to placate a sadistic tyrant, like sinners in the hands of an angry God. No, we follow a God who knows us intimately and desires our love.
Look, a car runs well on good gasoline, frequent oil changes, and well-made parts. Adding ethanol to the gas lowers performance; cheap gas dirties the engine; adding sugar to the gas ruins the car. Just so with us. We are created for love and responsibility. When we act not out of love but selfishness, when we shirk our responsibilities, we dirty the engine, so to speak. When we follow both the positive commands, "Thou shalt love with all thy heart, mind, soul, and strength" as well as avoid the objects of the negative commands, "Thou shalt not..." we live in accord with God's design for us. We live better. I dare say, we become happier.
Yes, the world and sin offer satisfaction and gratification, but such satisfaction is fleeting, shallow, short-lived. The happiness we find in Christ's love is the happiness we were created to seek out. God created a desire in our hearts for peace, happiness, fulfillment. Yet all those desires will find their final satisfaction in God. As St. Augustine says,
Great are you, O Lord, and exceedingly worthy of praise; your power is immense, and your wisdom beyond reckoning. And so we men, who are a due part of your creation, long to praise you – we also carry our mortality about with us, carry the evidence of our sin and with it the proof that you thwart the proud. You arouse us so that praising you may bring us joy, because you have made us and drawn us to yourself, and our heart is unquiet until it rests in you.
and in Matthew 11: 25-30
|25||At that time Jesus declared, "I thank thee, Father, Lord of heaven and earth, that thou hast hidden these things from the wise and understanding and revealed them to babes;|
|26||yea, Father, for such was thy gracious will.|
|27||All things have been delivered to me by my Father; and no one knows the Son except the Father, and no one knows the Father except the Son and any one to whom the Son chooses to reveal him.|
|28||Come to me, all who labor and are heavy laden, and I will give you rest.|
|29||Take my yoke upon you, and learn from me; for I am gentle and lowly in heart, and you will find rest for your souls.|
|30||For my yoke is easy, and my burden is light."|
God is not a henchman. More like it, he is like the ox pulling the cart with our broken body back from battle. He carries the yoke on his shoulder to rescue us. He gives us only a sliver to carry in return.