So here is the complete list of players that have scored more first division league goals than Lionel Messi, of all the players ahead of him, only Pele had scored more goals at the age Messi is currently.
Both Pele and Bican scored the majority of their goals in debatable championships, they are still include as they are both recognized as the best fotballers in their respective eras regardless of the circumstances they played in.
541 Pelé 1957-1977 (470 in state league and 34 in Brazilian championship and 37 in USA championship)
518 Josef Bican 1931-1955 (72 in Austrian championship and 446 in Czech championship)
514 Ferenc Puskas 1943-1966 (358 in Hugarian championship and 156 in Spanish championship)
417 Imre Schlosser 1906-1928 (145 in Austrian championship and 272 in Hungarian championship)
416 Gyula Zsengeller 1935-1952 (387 in Hungarian championship, 6 in Italian championship and 23 in Colombian championship)
410 Jimmy McGrory 1922-1938 (all in Scottish championship)
405 Gerd Muller 1965-1981 (365 in German championship and 40 in USA championship)
405 Roger Milla 1970-1996 (253 in Cameroonian championship, 111 in French championship and 41 in Indonesian championship)
400 Hugo Sánchez 1976-1997 (123 in Mexican championship, 234 in Spanish championship, 37 in USA championship and 6 in Austrian championship)
398 Cristiano Ronaldo 2002-? (3 in Portugese Championship, 84 in English championship and 311 in Spanish championship)
393 Ferenc Szusza 1941-1961 (all in Hungarian championship)
385 Carlos Bianchi 1968-1985 (206 in Argentinian championship and 179 in French championship)
383 Lionel Messi 2004-?
377 Di Stefano 1945-1966 (59 in Argentinian championship, 90 in Colombian championship and 227 in Spanish championchip)
376 Gunnar Nordahl 1940-1957 (149 in Swedish championship and 225 in Italian championship)