From the moment that B’nai Yisrael arrived in the wilderness, God protected them as we see in Shmot 13:21-22:
And God went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; that they may go by day and by night: He did not take away the pillar of the cloud by day nor the pillar of fire by night, from before the people.
In Nechemia 9:17-21 we see that despite their mistakes, God continued to protect B’nai Yisrael for 40 years in the wilderness and beyond:
…But You, being a forgiving God, gracious and compassionate, long-suffering and abounding in faithfulness, did not abandon them. Even though they made themselves a molten calf and said, ‘This is your God who brought you out of Egypt,’ thus committing great blasphemies; You, in Your abundant compassion, did not abandon them in the wilderness. The pillar of cloud did not depart from them to lead them on the way by day, nor the pillar of fire by night to give them light in the way they were to go. You endowed them with Your good spirit to instruct them. You did not withhold Your manna from their mouth; You gave them water when they were thirsty. Forty years You sustained them in the wilderness so that they lacked nothing; their clothes did not wear out, and their feet did not swell…
God forgave them for the sin of the Golden calf, continued to dwell within them and lit the way.
Yehuda HaLevi in Sefer HaKuzari puts the sin of the Golden Calf in perspective:
The worshippers of the Golden Calf were punished and put to death, 3,000 persons in all out of 600,000; but the manna did not stop, the pillar of fire continued to lead them and the prophetic spirit persisted in their midst. The only thing that they were deprived of was the two tablets which Moshe broke and interceded with God to restore. These were restored and that iniquity was expiated.
Ramban comments that as soon as the people caught sight of Moshe, they left the calf, rejected it and let him burn it and sprinkle its dust over the water. No one took issue with him, Moshe did not have to reprimand them or say anything to them. When he reached the camp and saw the calf and the dancing they immediately packed up and fled. He took the calf, burnt it and gave them to drink of it, which they did without a murmur. Had they acknowledged it as a god- no one would allow his king and god to be burnt.
As a nation that had been living in Egypt for generations, steeped in idol worship, it is not surprising that when some members of B’nai Yisrael didn’t see Moshe for 40 days while he was on Mt. Sinai they tried to replace him. However, as soon as he returned, they let him lead them back on the path to God.
We learn from this incident how loving and forgiving God was to B’nai Yisrael in the wilderness and beyond, even when they may not have been worthy.