Can the concept of original sin be Scripturally proven or not?

The word for 'weakness' (astheneo) of the flesh (Rom.8:3), or the 'infirmity' (astheneo) of the flesh (Rom.6:19) seems to indicate that the inclination to sin is in our fallen flesh nature and not from the concept of 'original sin' A few examples: "The spirit is willing, but the flesh is 'weak' (astheneo)" (Matt.26:41). "For what the law could not do in that it was 'weak' (astheneo) through the flesh, God sent His own Son in the likeness of sinful flesh, and for sin condemned sin in the flesh." (Rom.8:3). "For we have not a high priest who is unable to sympathize with our 'weaknesses' (astheneo), but one who in every respect has been tempted as we are, yet without sinning."(Heb.4:15)