The idealism generated considerable controversy in Germany and elsewhere in such a way that both followers and opponents emerged.
Among those who developed arguments in the opposite direction of Hegel, we can quote Herbart who will assert that reality is not 'set' by the 'I', postulating in favor of a clear realism. Also Schopenhauer will despise Hegelian idealism in favor of the Kantian theoretical framework. Kierkegaard will react equally against idealism and against formalist religiosity and a theology dominated by Hegelianism.
And among those who continued the line drawn by Hegel, it is possible to recognize a Hegeilian right and left.
The Hegelian right, represented by thinkers like Bauer and Erdmann, sought the justification of Christianity from the concepts of Hegelian philosophy. In fact, Hegelianism greatly influenced Christian theology as it had previously happened with Kant.
It is a radical variant that elaborates a critique of the religious. Strauss, for example, will reduce Jesus to the category of 'myth' and Feuerbach who will vehemently assert that Hegelian philosophy was the last rational refuge of theology.
Herbart, for a reality independent of the 'I'
Schopenhauer, romantic inspiration
Kierkegaard, a philosophy of faith
The Hegelian system as the last refuge of theology: the Hegelian left by Feuerbach