A refusal to take personal responsibility for one's failures is a sign of a lack of character. Unfortunately, this weakness is as old as man himself.
Adam and Eve were confronted by God when they sinned. God asked Adam if he had eaten from the forbidden tree. "Then the man said, 'The woman whom You gave to be with me, she gave me of the tree, and I ate'" (Gen. 3:12). Eve's response wasn't any better. "And the Lord God said to the woman, 'What is this you have done?' The woman said, 'The serpent deceived me, and I ate'" (v. 13). They tried to get God to believe it was someone else's fault they had sinned.
When Aaron was confronted by Moses for crafting the molted calf, he tried to blame his action upon the people (Ex. 32:22-24). When Samuel confronted Saul regarding his failure to obey the Lord's command, the rebellious king tried to blame the people (1 Sam. 15:15, 21).
This game does not work. We cannot avoid the guilt of our personal sins by trying to blame them upon someone else. Each one of us will stand before God and be judged as individuals (Rom. 14:10-12). We will bear the guilt of our personal sins (Ezek. 18:20).
Instead of being like Adam, Eve, Aaron, or Saul, we need to be like David when he was confronted with the reality of his transgression. He humbly replied, "I have sinned against the Lord," to which Nathan replied, "The Lord also has put away your sin; you shall not die" (2 Sam. 12:13).
All of us are going to sin. While people may influence us to do so, we sin because we choose to do so. Let's admit when we have sinned. This is how we maintain our character, and more importantly, it is the only way we can receive forgiveness for our sin (1 John 1:9).