Does God withhold blessings from me when I sin?

No.

How could he? Every blessing that I receive from God, I receive purely as a matter of grace. Election? Grace. Justification? Grace. Adoption? Grace. Sanctification? Grace. Glorification? Future Grace.

If our loving heavenly Father withheld his blessings from us because of our sin, I dare say that none of us would have ever received anything good from God at all. Nevertheless, I fear that many of us (myself included) live our lives as though we believed in a God who meted out his blessings to us based on our performance.

Consider. If you had an important meeting later this week regarding a promotion, what would you do? Many of us would instinctively feel that we better "step it up" this week, read our Bibles more than usual, have extended times of prayer, to make sure that come meeting day we will be on good terms with God. Habits like these go to show that despite what we say (and sing in church), we live our lives as though we have a works based relationship with God.

How good do our 'good' days have to be to merit God's blessing? "Be perfect as your heavenly Father is perfect." Are they that good? How bad does a bad day have to be to drop off God's blessing list? I know we don't think in these terms. At least I don't. But my actions betray such things. Jerry Bridges says "it is because we do not fully grasp the fact that Jesus paid the penalty for all our sins that we despair of God's blessing when we have failed to live up to even our own desires to live a life that is pleasing to God."

I can say with confidence that I will sin tomorrow. I will not deserve anything from God. But at the end of the day (at at the beginning of it, and during the middle) God will look at me and see only the righteousness of Christ which has been imputed to my account. All my sins have been forgiven. What I have done or not done will not matter, my relationship will be by grace. God will take delight in blessing me no less than he takes delight in blessing Christ.

"Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places." - Ephesians 1:3