You likely start out with credibility in the eyes of the judge. After all, you’re an officer of the court. But that initial benefit of the doubt can easily slip away, and once you’ve lost your credibility, the case may not be far behind.
Play it safe and make an offer of proof whenever you’re introducing evidence. Even if your evidence is excluded after a motion in limine or a trial objection, an offer of proof will preserve the record for appeal.