power.

Acts 1:8

"But you will receive power when the Holy Spirit has come upon you..."

The greek word for "power" in this verse is dunamis, which is where we get the word dynamite.
Every Christian has the Holy Spirit within them. The question is, are we utilizing the power of the Holy Spirit? Are we allowing the Holy Spirit to work his power through us? Or are we doing what 1 Thessalonians 5:19 says not to do...

"Do not quench the spirit."