There was resistance. It wasn't as wide spread as you might see in other, less thoroughly occupied nations (Iraq comes to mind), but it was there. It was just muted due to a number of factors.
The Powers had well over 2 MILLION soldiers on the ground in Germany.
The USSR alone had THREE Guards Tank Armies (1,800 tanks, 9 divisions per Army, 27 Divisions total), THREE Shock Armies (27 motor rifle division in total), one Guards Army (9 divisions) and 47th Army (9 infantry divisions, 1st Guards Tank Corps (three tank divisions) and 25th Tank Corps (three tank divisions) or SEVENTY SEVEN divisions in the Soviet Zone. Even accounting for empty files due to combat losses, on July 1, 1945 the Red Army numbered at least 1.2 million troops on occupation duty. The NKVD also had a substantial force in the Soviet Zone, part of the Cheka's empire was a series of 10 "special camps" that held between 120,000 & 180,000 detainees that the Soviets thought to be troublesome (largely local Nazi leadership and SS, but also anyone the NKVD though would cause trouble). Roughly a third of these detainees died in custody. This does not include the roughly 2.8 million PoW held by the Soviets or the 350,000-1,000,000 of these men who died in Soviet custody.
While the WAllies had slightly fewer troops than the Soviets dedicated to Occupation (the U.S. had 614,000 troops in Germany on January 1, 1946) they also interned around 100,000 Germans (suspected Nazi leaders and SS made up the bulk of these detainees), a highly debated number of these detainees and of PoW retained in France and Britain as forced labor died before release (best estimates are around 1% of those in U.S./UK control and 2.6% in French control, other, vastly higher estimates have been fairly well debunked).
When you look at the detainee profile and the huge number of PoW retained (in the case of the USSR for up to 10 years, for the British and French until 1948) it is clear that the main potential resistors, young men, were not in any position to resist (millions were, in fact, not even in Germany).
A second, not to be ignored, factor is the food situation in Germany. A combination of Nazi resource allocations, infrastructure damage, and Allied neglect (some, sadly, quite intentional) combined to put Germany on starvation rations in the months immediately following the war as calories dropped on average to around 1,000 daily. When one is barely getting enough food to survive it is difficult to be part of an active resistance.
You also have the morale issue among most Germans by the end of the war. They were utterly defeated, not just on the battlefield, but inside their own heads. They had been bombed, strafed, lost many of the young men in their families to combat deaths, had troops billeted in their homes, been treated with anything from indifference to hostility to utter brutality by the occupying forces. They were done with war, done with fighting.