Germany tests on Friday against Spain and on Tuesday against Brazil. This makes it clear: As defending champions, they want to test themselves against the strongest opponents to get a good assessment of their position for the tournament in the summer in Russia.
Other World Cup participants are also using the upcoming matches to test their World Cup form: While Germany plays Spain on Friday, England, for example, faces the Netherlands - even though the Netherlands won't be at the World Cup this time, they will still be a challenging opponent for the English. Argentina is also testing its World Cup form against a non-World Cup participant: Italy hosts Messi's team and will certainly want to show that they shouldn't really be missing out on the start in Russia.
Co-favorites France have chosen Colombia, a World Cup participant who should certainly be beatable. The same applies to European champions Portugal, who will play against Egypt. Brazil will first play against World Cup hosts Russia.
On the second matchday, Germany then faces Brazil. Like England before them, the Portuguese have also chosen the Netherlands as another test opponent. Hosts Russia underline their own ambitions by playing Brazil in the first test and then facing France. England tests again against a non-World Cup participant - but still against a strong team in Italy. Spain also underlines their own ambitions through the test against Argentina - and vice versa.
In the group stage of the 2018 World Cup in Russia, Germany plays Mexico, Sweden and South Korea. Mexico prepares for the World Cup in Russia with matches against Iceland and Croatia. Sweden plays against Chile and Romania. South Korea gets on World Cup course against Northern Ireland and Poland.
And otherwise: Many World Cup participants test themselves against each other: Denmark plays Panama, Tunisia against Iran. Serbia tests against Morocco, Poland against Nigeria. Peru and Croatia prepare themselves against each other for World Cup form, Switzerland and Panama likewise. Belgium plays against Saudi Arabia, Tunisia against Costa Rica and Iceland against Peru.
Hardly any team treats itself to such an intensive program as the German national team. For this reason, after the two test matches, one can certainly draw initial conclusions about how things stand with the defending champions at the World Cup.