Jesus' resurrection seems to be the primary objection to Christianity expressed by non Christians. They don't believe he was physically resurrected and find believers' claims that he was incredible. The use of language gets pretty slippery pretty fast after that. I am comfortable with the formulation "he died for me" as I think that of many other people who have never met me. I also don't feel like I am bearing false witness when I "use my tongue as a pen for skillful writers" to enunciate the old creeds. I don't actually know what I am enunciating any more than anyone else as far as I can tell. But I cannot and do not accept that Jesus' lived his life and preached the Sermon on the Mount in vain. At least in the that sense his spirit has and will evermore be victorious over death as far as I am concerned. When future scientists take some of the mystery out of my faith or discover some hitherto undiscovered basis for it, I do not believe they will find the commandments to be false. I am with Job on that score, that God has to be accepted as he is and our duty is to fear him and keep the commandments even in the face of not understanding him.
Let us suppose the non Christians are right about the physical resurrection, that Jesus body wasn't reanimated, that it disintegrated as all living bodies appear to. What happened to the love Jesus had for creation and everyone in it past and future? Jesus taught in Mark 10:19 that eternal life is in keeping the "secular" commandments, so there!