In a 1 on 1 scenario:
I see MJ winning in this situation. Michael Jordan is an incredible scorer. One could argue that he is the best scorer of all time. The only acceptable alternate to Michael Jordan when it comes to pure scoring ability is Kevin Durant. If someone were to tell you that a man was the greatest scorer of all time and they didn’t mention “Michael Jordan” or “Kevin Durant”, then the person you were talking to was a liar.
5 on 5 Scenario:
The 5 on 5 scenario is definitely the most important scenario, I will not lie. If you were to match up Michael Jordan with Lebron James and each of them had the same 4 teammates then yes, I do think Lebron would win. The problem with this though is that Michael Jordan and Lebron James did not have the same play style. Michael Jordan was on a team where he had to score. Everybody talks about how Scottie Pippen was the reason the Bulls (and Michael Jordan) won 6 championships, but the fact is this man was a worse version of Danny Granger on the offensive end. The guy averaged 16 points a game in his career. You know who averaged more points per game than Scottie Pippen in their career? Danillo Gallinari, Carlos Boozer, Brook Lopez, and a long list of players that are mediocre at best. Also, Illini great Deron Williams. Yes, Scottie Pippen was perhaps the best on ball defender of all time, but Michael Jordan carried every Bulls team on the offensive end. I don’t think Lebron would have been able to do the same. Lebron would have maybe been able to figure out a way to get his teammates involved if he were to take MJ’s place on those 90’s Bulls teams and win 6 championships like MJ did, but I truly find it hard to believe that if you were to replace Lebron James with Michael Jordan then the Bulls would still have won 6 championships. However, if you were to replace Michael Jordan for Lebron James on the 2010 Heat, then I think the Heat win that series. They lacked a true scorer, and Michael Jordan would have filled that void. 2014 could also be argued, but the Spurs were incredibly good that year. Overall, MJ is the GOAT.