for no reason at all 无缘无故地

There is absolutely no such thing as love or hatred without any reason or cause.
世上没有无缘无故的爱，也没有无缘无故的恨。

blood relationship 血缘

After all, we are sisters, have a blood relationship, even if we do not close, can not erase our relationship.
我们毕竟是姐妹，有着血缘关系，就算我们不亲，也无法抹灭我们之间的关系。

tie the nuptial knot 喜结良缘

Under French law , couples must tie the knot before a mayor to make their union official .
根据法国法律，新人举行婚礼必须有市长见证，才可正式结为合法夫妻。

Fate brings together people who are far apart.
有缘终相逢。

A good marriage arranged in Heaven
天赐良缘。

I can't tell the true shape of Lu Shan ,because I myself am on the mountain.
不识庐山真面目，只缘身在此山中。

Two beings destined to marry each other, though thousands of miles apart, are tied together with an invisible red thread by an old man under the moonlight.
千里姻缘一线牵。

As decreed by providence you have met him; otherwise you might have failed although you traveled a long way.
有缘千里来相会，无缘对面不相逢。

It is a pity that we have no opportunity to meet each other.
真遗憾,我们一直无缘相见。

As luck would have it, I found a job.
机缘凑巧，我找到一份工作。

They are attracted to each other but are not fated to be conjugally tied.
他们俩有情无缘。

Smoking and drinking don't appeal to me.
我与烟酒无缘。