情深未必能久伴久伴一定是情深
[qíng shēn wèi bì néng jiŭ bàn jiŭ bàn yī dìng shì qíng shēn]
This expresses a philosophical take on love: profound affection does not always last forever or ensure longevity; however, enduring companionship signifies true depth and sincerity of feeling.