The answer was simple - preach the Gospel! Preach Christ crucified and risen. Preach grace.
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them."
This was also a very important sermon for me - it was the first time preaching in the Czech language!
Pray for these students, and all the students that we come into contact with - that they would see the grace of God and have no choice but to respond.
Speaking on grace revealed to me how little I do understand grace. I suppose I never will comprehend it fully - but I will continue to seek for my eyes to opened so I may love my Lord more. Praise Jesus that the power of grace does not rest upon my own comprehension of it!