Why does my code work with document.write but not the document.getElementByID?

var questions = [
    ['How many legs does a cat have?', 4],
    ['What is my age?', 26],
    ['how many years of driving?', 1]
  ];
var correctAnswers = 0;
var question;
var answer;
var response;
var htmlCorrectAnswers;
var questionsCorrect = [];
var questionsIncorrect = [];

function print(message) {
    // this works correctly
    document.write(message)

     // this method does not work correctly
  // var outputDiv = document.getElementById('output');
  // outputDiv.innerHTML = message; // this method does not work correctly

}

//This for loop compares your answer and push's the question to the appropriate variable depending on whether it was correct or incorrect
for (i = 0; i < questions.length; i += 1){
  question = questions[i][0];
  answer = questions[i][1];
  response = parseInt(prompt(question));
   if (answer == response){
     questionsCorrect.push(question)
     correctAnswers += 1
   } else {
     questionsIncorrect.push(question)
   }
}

htmlCorrectAnswers = '<b><p>You got ' + correctAnswers + ' question(s) right</b></p>';

// This is a function that prints correctly answered questions
function printCorrectAnswers (list){
    if(questionsCorrect == 0){
        print('<p><b>You did not get an answer correct ahahah! </b></p>')
    } else {
        var listHTML = '<ol><b>You managed to get the following questions right:</b>';
        for (i = 0; i < questionsCorrect.length; i += 1 ){
            listHTML += '<li> ' + list[i] + ' </li>';
        }
        listHTML += '</ol>';
        print(listHTML);
    }
}
// This is a function that prints incorrectly answered questions
function printIncorrectAnswers (list){
    if(questionsIncorrect == 0){
        print('</p><b>You did not get an answer wrong</b></p>')
    } else {
        var listHTML = '<ol><b>You got the following questions wrong:</b>';
        i = 0;
        for (i = 0; i < questionsIncorrect.length; i += 1){
            listHTML += '<li> ' + list[i]  + ' </li>';
        }
        listHTML += '</ol>';
        print(listHTML);
    }
}

print(htmlCorrectAnswers);

printCorrectAnswers(questionsCorrect);

printIncorrectAnswers(questionsIncorrect);