I would tell them that life's highest joy comes only from knowing Christ and seeking to do His will and then I would urge them to commit their lives to Him without reserve.
Yes, young people today face many challenges and temptations and those are probably only going to get worse. But down inside they have the same aspirations and desires people have always had to be happy, to live a fulfilling life, to know why they are here and what life is all about. And only God can meet those desires and needs and He will, as we turn in faith to Christ.
Tragically, in their search for meaning and happiness, many youth end up taking the wrong road in life. As Jesus warned, "Wide is the gate and broad is the road that leads to destruction, and many enter through it" (Matthew 7:13). And yet we have found repeatedly in our Crusades that young people today are spiritually hungry and open to the message of Christ, and we have seen countless thousands give their lives to Him just in the last few years.
Pray for our youth, that they will not be misled but will turn to Christ for the meaning and joy they seek. And pray also that God will use you to point others including the youth around you to Christ, who alone is "the way and the truth and the life" (John 14:6).