He never promised that the cross would not be heavy?

The phrase suggests that while faith may offer comfort and guidance, it does not guarantee an absence of suffering or hardship. Instead, it emphasizes the idea that challenges and burdens are a part of the human experience. The promise lies in the strength and support found in faith during difficult times, rather than the absence of difficulties themselves. Ultimately, it encourages resilience and reliance on spiritual beliefs amidst life's trials.