中譯英,謝謝!!

A group of sisters and brother, they are good at playing ,playing exciting games,there are full of happiness.

There are traditional'dance lions' to give to, also has solemn and ceremonious church to registrate . Mary and John go to another step of life from that time.I am going to express good wishes to Mary and john here.

The following will be the version that I recommend you to use:

[We have] a group of fun-loving brothers and sisters and(willing to play) exciting games; the ceremony is enriched (permeated) by joy and happiness.

[We have] traditional lion dance accompanying with the wedding ceremony in a (this) magnificent and solemn church. [With these, we witness] Mary and John entering the next stage of life. Here, let me(us) wish Mary and John all the happiness and bliss in life.

Please note that I have made a few adjustments,
1) The words that I put in square brackets are not in your original script. I have added them so that the speech will flow smoothly.
2) Words in round brackets are options. Depending on the situation, you may want to opt for alternatives.
3)) Instead of making lion dance parallel with the wedding ceremony, I have made the lion dance as a supplementary element.
4) 白頭到老 should be translated as "remain a devoted couple to the end of their lives". However, as noted by another translator here (Godfrey), you may want to avoid this because putting it into the speech may be seen your lack of confidence that the marriage will last. If you want to say something else. Check out sayings in greeting cards. Type in "wedding" and "greeting" and you should find other options.

Congratulations to your friends!

2010-08-03 03:37:11 補充：
As another commentator(Ahliu) have pointed out, you may want to change 'brothers and sisters" to "groomsmen and bridesmaid" or simply friends.

2010-08-03 03:39:18 補充：
Another advice: avoid the word "embark". It may have a wee bit of negative connotation- "embark" is often associated with investment or going on a broad ship. "The general embarked his troops" So just be careful

/_\\ 唔係「brothers and sisters」，係「groomsmen and bridesmaids」呀大佬......

A group of fun-loving brothers and sisters, playing exciting games in an atmosphere filled with joy.

There is traditional lion dance for entertainment, also a solemn wedding in the church. From now on, Mary and John together embark onto another stage of life. Here I wish them all the very best and live happily forever. (Till death do they part)

(Till death do they part) 中國人不喜歡提及 death, 還是遺漏這句子

2010-08-03 12:25:33 補充：
Embark on = start or engaged in (especially something new, difficult, exciting)

A group of educators embarked on a mission to build the self-confidence of promising students.

I don't think “embark” has negative connotation in the above sentence.

2010-08-03 12:31:43 補充：
Embark:

I quite agree with Josephine’s choice of the word “enter” instead of "embark" – much safer and everyone understands it. Well, her version is the best of all, especially the comments.

Josephine , What do you mean by “broad ship”?

2010-08-03 12:54:49 補充：
Accompanying with:

Josephine, hope you don't mind if I ask another question. We seldom use the word "with" after accompany, except when in passive voice. accompanied with/by.

He accompanied her on a trip.
The president, accompanied by his bodyguard, left the house.

I am not so sure. Thanks.

very good time a group of brothers and sisters, exciting game, full of happy atmosphere