Do you remember your first day at school? I experienced fear of the unknown, lack of confidence and being unsure of what lay ahead. I was shy and scared on my own and everyone looked bigger than me. Yet after a while I felt more confident around the classroom with my teacher and I made friends. The fear went and for the first time I felt more comfortable. As time went by what I learnt and I used it enhanced my ability to deal with every situation.
I believe it was just like that for the apostles on Pentecost Sunday. Gathered together in a room unsure of what to do now Jesus had gone they felt uncertain. However when they became filled with the Holy Spirit they were prepared to take risks and able to do things beyond their comprehension, e.g. speak in foreign languages without learning them first. Imagine if we could do that.
They proclaimed that Jesus was indeed the Son of God and through his resurrection was the way to eternal life. Through such a proclamation they were placing their own lives in jeopardy. Yet for the first time people were hearing about eternal salvation.
Like with our learning we have a choice to listen to the word of God, hence increasing our life choices which gives greater meaning and purpose to our lives.