We need to be realistic and recognize that there will be times when we won't be sharing our faith out of an overwhelming sense of joy. When that happens, that's a call to look at our own devotional lives. Are we putting our hearts and minds before the Lord and under his cross everyday? Do we remind ourselves continually that we have been ransomed by the death of the Saviour? When we meditate on Christ's death for us, it doesn't mean that we never have struggles in our obedience, but it does help.