Whitebeard said this quote

“ You're not the one Teach!!The man roger was waiting for,at the very least,it's not you teachJust as there are people who inherited roger's will...Someday one will carry ace's will...You may eradicate their bloodline ,but their flame never dies...For many ages , it has been passed down through the generations...And someday,bearing the weight of all these generations,a man will appear to challenge this world...Sengoku,you people of the World Government are living in fear of that great battle that will someday engulf the entire world...Though it has nothing to do with me... When somebody finds that treasure... The world will be turned upside down!!...OH yes!it will be found!That day will come!!!!ONE PIECE!IS OUT THERE!!!!!! ”