Many people around the world consider Christianity "just a religion." Many see Christianity as a set of rules, a set of rituals, a set of mystical or weird beliefs that Christians follow. While we Christians know that to be so untrue, some of those views should be blamed on us, because we've never really lived the way we should have: a life of power.
Paul said in 1 Corinthians 4:20 that "the kingdom of God is not a matter of talk but of power." It's not just a matter of preaching, or sharing the gospel with words like "God loves you" and "Jesus died for you" and not showing them God's authentic love. That's not the way the Bible presents it to be.
During Jesus' earthly ministry, He showed what was absolutely mind-blowing for that time and age. The Pharisees expected that the Messiah would be a warrior king who will restore the kingdom to Israel. Even the disciples thought that Jesus would do that too (see Acts 1:6). Yet He did what the people did not expect.
A powerful life
God Himself came in the form of a man, powerless and weak just like us, in Jesus. While some might think that Jesus had power as God, He actually limited Himself to time, space, and a host of other needs just like we are limited – and with that form He did the impossible.
Unlike the religious leaders at the time, Jesus spent time with sinners, loving them and showing them that God loved them.
Unlike what normal people do, Jesus healed the sick, cast demons out of people who were tormented, supernaturally multiplied bread and fish to feed multitudes, and walked on water. He even allowed Peter to walk on water, and when the latter almost drowned, He picked him up.
Although He did not deserve it, Jesus received 39 lashes on His back for our iniquities, was ridiculed for our shame, carried the cross for our sake, was nailed to the cross and died for our sins. He even released forgiveness while His blood was pouring out of His battered and mutilated body. (Isaiah 53; Luke 23:34)
Unlike the dead, Jesus rose from the grave in power, and went out of a tomb that was sealed with a stone. (Matthew 28:2-7)
No powerless Christianity
This same man, who died and rose, was given all authority in heaven and on earth. With that same authority, He commands all of us to "go and preach the gospel into all creation," promising that He will be with us "until the end of the age." (Mark 16:15; Matthew 28:18-20)
With that same authority the Lord Jesus said that signs will believe those who follow Him. "And these signs will follow those who believe: In My name they will cast out demons; they will speak with new tongues; they will take up serpents; and if they drink anything deadly, it will by no means hurt them; they will lay hands on the sick, and they will recover." (Mark 16:17-18)
Because of the Holy Spirit – the same power that raised Christ from the dead – we could see sin defeated in our lives, and we could live a holy life, set apart unto the Lord. (Romans 8, Galatians 5)
These things the believers in the book of Acts saw. These signs became evident in the lives of Paul, Peter, John, Philip, and others. They lived powerful Christian lives.
Because of what Jesus has done according to the plan of God and the power of the Holy Spirit, there's no such thing as powerless Christianity.