Jesus, himself, modeled the way we should act. He was gentle, forgiving, truthful, at times angry and blunt (when people were just being jerks). He wasn't a doormat. When challenged about His teaching or acts, He always answered directly and without apology, because He knew His words and deeds were righteous...or right. There's a key point, when we live upright lives, following His lead, we won't have to be covering up or trying to make excuses for ourselves.
Of course, as humans, we WILL make mistakes, bad choices, and do things we know we shouldn't have. When that happens, we are to ADMIT IT (not defend ourselves or make excuses), apologize, ask forgiveness (from God always, and others if they've been wronged), and make things right in those circumstances where that's possible.
Also, Jesus never failed to give the credit, or glory, to God.
The entire Bible is the story of Jesus. The Old Testament is a 'foreshadowing'...kinda like a foretelling in code...of Christ's coming, life and salvation of man. The New Testament tells the actual events of His birth, teaching, death, resurrection and instructions to us as believers.