Be the living expression of God's kindness; kindness in your face, kindness in your eyes, kindness in your smile.
Once we take our eyes away from ourselves, from our interests, from our own rights, privileges, ambitions - then they will become clear to see Jesus around us.
If you are joyful, do not worry about lukewarmness. Joy will shine in your eyes and in your look, in your conversation and in your countenance. You will not be able to hide it because joy overflows.