"Without consistency there is no moral strength."
~ Robert Owen, Welsh socialist and social reformer. (1771-1858)
Hypocrisy is one result of inconsistency. Act different around one person, say one thing when you believe another to avoid debate or be accepted.
Failure is also a result of inconsistency. Success doesn’t always happen overnight. Persistence, learning from mistakes and a lot of hard work are all pieces of success.
Inconsistency as well as harsh defensiveness can also be a sign of uncertainty in beliefs. I see this as a sign of not knowing ones beliefs. Perhaps a time to discuss, research and truly discover what one consistently believes.
This may all sound obvious and typical dialogue to you. However, it’s often ignored because many people do not stand their ground. Once you discover "it," be consistent in what you believe. "It" is your foundation of strength and character.