Happiness is not mandatory for the grace believer. Perhaps we think because we have been given so much we should be happy. Happiness can become some sort of badge of success or confirmation of blessing in some circles.
Just to put it out there... I have great joy but I am not always happy. Happiness is not my 'goal' in life.
I don't want to counsel people toward happiness either. I want to communicate the profitability and sensibility of faith even if it is just by living it out in front of them. I want to connect with people... sit where they sit and share their joy or sadness as someone who is believing with them or even for them if they have little capacity in the moment.
"The night is far spent, the day is at hand: let us therefore cast off the works of darkness, and let us put on the armour of light." - Romans 13:12 KJV
"For as many of you as have been baptized into Christ have put on Christ." - Galatians 3:27 KJV
"And that ye put on the new man, which after God is created in righteousness and true holiness." - Ephesians 4:24 KJV
"Put on the whole armour of God, that ye may be able to stand against the wiles of the devil." - Ephesians 6:11 KJV
"And above all these things put on charity, which is the bond of perfectness." - Colossians 3:14 KJV
Forget putting on a happy face... put on Jesus Christ. Then even our mood can be dictated by the mind of Christ as we walk in the Spirit.