Arduino gist for proper usage of vertical scrolling on each output with 16x2 LCD display.

16x2lcdPrint.ino

#include <LiquidCrystal.h>
String Line1;
String Line2;
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void lcdPrint(String lcdText) {
    lcd.clear();
    Line1 = Line2;
    lcd.setCursor(0, 0);
    lcd.print(Line1);
    Line2 = lcdText;
    Line2.replace("\r\n", "");
    lcd.setCursor(0, 1);
    lcd.print(Line2);
    Line1 = "";
    lcdText = "";
}

void setup() {
    lcd.begin(16, 2);
    lcdPrint("LCD Initialized!");
    lcdPrint("DEMO LINE 1");
    lcdPrint("DEMO LINE 2");
    lcdPrint("DEMO LINE 3");
    lcdPrint("DEMO LINE 4");
    lcdPrint("DEMO LINE 5");
}

void loop() {
}