Yes, there is much meaning to the life of a Christian. We can make a difference in many ways. We should live our lives according to God's will, and in doing so, we can have a real positive impact on the world. We are each given different gifts / talents / interests, and we should use these in beneficial ways.
One of the biggest ways we can make a difference is to reach others for God:
[Pro 11:30 NKJV] 30 The fruit of the righteous [is a] tree of life, And he who wins souls [is] wise.
[1Pe 3:15 NKJV] 15 But sanctify the Lord God in your hearts, and always [be] ready to [give] a defense to everyone who asks you a reason for the hope that is in you, with meekness and fear;
[Jhn 3:16 NKJV] 16 "For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.
If you even reach one person with the Gospel, and they are saved, you have made a huge difference, in that someone who would have spent eternity in Hell now gets to spend eternity in Heaven.
We are also encouraged to help those in need (e.g. feed the hungry, etc...).
In summary, I believe we are to make a positive impact in the world, and to glorify God with what we do in our lives. We should also responsibly enjoy the blessings that God has given us.
[Phl 4:4 NKJV] 4 Rejoice in the Lord always. Again I will say, rejoice!
There is much more to meaning in the life of a Christian, but this is a start. I would like to see the answers other people provide as well! FYI: I am a Baptist, but lean toward non-denominational (e.g. the main thing is to trust in Jesus for our salvation, denomination isn't so important as long as they have this right).