Let me begin by saying, lest you think we don't believe it, that God is sovereign.
God can fix the messes we make, whether they're financial, spiritual, political, ecological, etc.
But the minute we make those messes, assuming that God will fix it anyway, we are in some fundamental way sinning. Paul writes, "Shall we continue in sin so that grace may abound? May it never be!" Allow me to paraphrase: should we keep screwing stuff up because God will fix it anyway? I hope the answer on your lips is a resounding "No!"
Charity brings up possibly the most important area of life that Christians make excuses for... evangelism. I don't have to share my faith because God is sovereign and if so and so is supposed to get saved, God'll take care of it.
Remember with me for a second your own faith story. What if someone influential in your life hadn't shared God with you? Do you still think you'd be where you are with your own faith? In exactly the same place? Or do you think you might be a few steps behind? Do you think you might have had the chance to make a few more mistakes that would cost you down the road? Yeah... that's what I thought. So yeah... God's will is that no one should perish. And He will save people.
Ephesians 2:10 says that we are God's workmanship, created in Jesus' likeness to do good works which he has prepared in advance for us. To make excuses as to why you can't give, why you can't help, why you can't share your faith, you are disobeying God. And when the excuse you are using is God's sovereignty as your excuse, you're adding metaphorical insult to metaphorical injury.
The next time you use the phrase "God is sovereign," I want you to stop and think. Did I say that because I'm doing everything God has asked me to and the results are up to him, or did I say that because there's something I don't want to do but I still want to sound spiritual?