我相信你一定会幸福快乐的~!帮我翻译成英文，谢谢~

Give you my best wishes and you will get happiness forever.

我最好的祝愿就是你能永远幸福。

I believe you will be happy
我相信你一定会幸福快乐的

我建议 I wish you happy and I deeply believe so.
比较口语和感兴，意为： 我愿你幸福长久，我也深信如是～

I believe you'll be full of happiness.

I believe that you'll be happy!

I believe you will be happy!