你若不离不弃我便生死相依
[nĭ ruò bù lí bù qì wŏ biàn shēng sĭ xiāng yī]
This reflects the deep emotion or commitment that someone is willing to stick by another no matter what happens - similar to 'in sickness and in health' in English weddings vows. Here it implies a firm determination, usually towards an ideal relationship