Mandaly, how is the verb 'to be' specifically used in these expressions: Be patient, Be happy or Be blessed. Speaking to a congregation I want to say, "Be happy in the Lord!" The translation I got was "Ou dwe kontan nan Senyè a!", but i don't want to say "You must be happy...". I want to say "Be happy..."

I see...
These sentences comes across as either an advice, an encouragement, or a benediction....
In that case you would say:

1. Be happy in the Lord.
    Se pou nou kontan nan Senyè a. (nou is plural as it seems that you're speaking to a crowd)


2. Be patient.
    Se pou ou pasyan. (singular)
    Se pou nou pasyan. (plural) 
    or you can also say:
    Se pou'w pasyante.
    Se pou nou pasyante.

3. Be blessed. (blessed by God, right?)
    Se pou Bondye beni'w. (singular)
    Se pou Bondye beni nou (plural)
    or you may rephrase this:
    Se pou'w jwenn benediction. (May you find blessing.)

other examples (using Se pou....)

4. Be there before 9 PM.
    Se pou nou la anvan nevè di swa.


5. Be kind to them.
    Se pou'w fè jantiyès avèk yo.


6. 'Be quick, but don't hurry'
    'Se pou'w rapid, men pa prese'
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