Numerically, the Russians had an immense army on their frontier. Leaders of nations and Generals everywhere always think that the ability of their army is equal to its numerical strength. Unfortunately, this is rarely the case. More troops on the border meant more POWs and KIAs for the Germans to haul off.
The Red Army in 1941 was in terrible shape logistically, maintenance-wise and, even in material. The manpower was neither motivated or well led (incidently, the purge really didn't cause this most of the officers were simply incompetent to begin with). Training was abysimal. Few units could even begin to use much of their equipment effectively.
One can look at Kalkin Gol where what amounted to a single reinforced Japanese infantry division was destroyed only after a sustained and repeated effort by roughly a Soviet army; about 5 to 8 times the Japanese force. The Soviets lost hundreds of tanks and thousands of men defeating this Japanese unit. The Red Air Force lost hundreds of aircraft to less than one hundred Japanese fighters committed. It was a slaughter in the air fully equal to that the Luftwaffe perpetrated on the Soviets in 1941. Polikarpov, the then premier Soviet fighter designer was sacked personally by Stalin over this incident and the miserable performance of his fighter designs. Zhukov, who was one of the primary agents in Kalikin Gol proved a mediocre general capable only of winning primarily through overwhelming force applied in a ham fisted manner.
I personally think that if Hitler himself had called Stalin and told him he was going to invade next month giving the date and time the Red Army would have been slaughtered every bit as badly as it originally was.