"For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord." (Romans 8:38-39) These verses leave me thunderstruck. There is such a calming reassurance that never fails to blow my mind. There is great confidence to be derived from the knowledge that "if God is for us, who can be against us?" as the chapter earlier states.
Death has been conquered, once and for all. Life has inevitable heartache and heartbreak, but you know what? The everyday struggles of life do not possess the power to separate us from the vast love of God, either. Angels and demons? Present circumstances and anxieties about the future? You have no reason to worry. God is, and always has been, in control. Paul gives us an important reminder that nothing – nothing that can even be thought to have enough power – can separate us from God's love.
We neither deserve nor earn that love. It was manifested ultimately at the cross of Jesus Christ; His final payment for sin – the outpouring of God's wrath on His only son – was what ensured our standing with God as righteous. Sin separates us from God, which should drive us to run from it. It causes a rift between God and the believer, but it does not change God's hold on that believer.
Our own personal sin, however base and instinctual the desire may be to give in to fleshly desires, cannot remove us from the love secured for us in Christ. If that isn't a reason to give thanks, I don't know what is. If you have acknowledged your sin and repented (Acts 20:21), cling to this promise, and have every reason to be as convinced as Paul was about its truth.