Many Christians let their past failures accumulate to the point where they have a hard time resisting temptation. They think, "What difference would one more sin make?"
There's a way to beat that. 2 Cor 5:17 says, "Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come." That's a beautiful statement, but God alsosays, "you also must consider yourselves dead to sin and alive to God in Christ Jesus." (Rom 6:11)
We ARE new creations. We ARE dead to sin. But we have to actually believe it—we have to consider it, buy into it, and act in faith on that. Do you really consider yourself as dead to sin? If not, start today.