“No temptation has overtaken you except such as is common to man; but God is faithful, who will not allow you to be tempted beyond what you are able, but with the temptation will also make the way of escape, that you may be able to bear it”

I think this verse provides a clear answer to the question of “Who is responsible for our sin?”

I never realised anyone could be in any doubt of the answer, until I met a fellow who shifted the responsibility from himself onto God, so you may meet such people too.
This verse shows that we have no excuses for our sin. As God always provides a way out, we always have a choice, and to give into temptation is a personal choice for which we are entirely responsible.
So, we cannot excuse ourselves by saying that our sin is due to our fallen human nature, or mankind’s state of original sin. It means we sin because we personally choose to do so, the guilt of our sin is entirely our own.

And the weight of that sin is an unbearable burden. When I compare the path that God has prepared for me, in line with his command in Matthew 5:48, “Be perfect, therefore, as your heavenly Father is perfect”, I realise that every day I continually sin.
This continual failure is also described by Paul about himself in Romans 7:19, “For what I do is not the good I want to do; no, the evil I do not want to do – this I keep on doing.”
But our hope in all this is also stated by Paul in 7:24, “Who will rescue me from this body of death? Thanks be to God – through Jesus Christ our Lord!” For Jesus took that unbearable weight for each one us upon himself on the cross, that we may be judged as righteous before God. And in rising from the dead, He overcame the power of sin and death over us, that we may be given real and eternal life through Him.

Praise God!