What does the Bible say is the true meaning of "living life"?
The meaning (or purpose) of every human being's life, according to Scripture, is to come to know God's provision of eternal life through His Son Jesus Christ.
Acts 17:24 “The God who made the world and all things in it, since He is Lord of heaven and earth, does not dwell in temples made with hands;
Acts 17:25 nor is He served by human hands, as though He needed anything, since He Himself gives to all people life and breath and all things;
Acts 17:26 and He made from one man every nation of mankind to live on all the face of the earth, having determined their appointed times and the boundaries of their habitation,
Acts 17:27 that they would seek God, if perhaps they might grope for Him and find Him, though He is not far from each one of us;
Acts 17:28 for in Him we live and move and exist, as even some of your own poets have said, ‘For we also are His children.’
Acts 17:29 “Being then the children of God, we ought not to think that the Divine Nature is like gold or silver or stone, an image formed by the art and thought of man.
Acts 17:30 “Therefore having overlooked the times of ignorance, God is now declaring to men that all people everywhere should repent,
Acts 17:31 because He has fixed a day in which He will judge the world in righteousness through a Man [Jesus] whom He has appointed, having furnished proof to all men by raising Him from the dead.”
This is the first and fundamental purpose of every human life, because without faith in Christ, there is no future for that person. When an unbeliever dies, they enter into an eternity separated from God and without rescue from never-ending torment.
Having come to Jesus by faith, believers then spend the rest of our lives on earth serving Him in preparation for the Kingdom to come. Our service brings an expectation of eternal reward, and the writer of Hebrews reminds us that faith must come first:
Heb. 11:6 And without faith it is impossible to please Him, for he who comes to God must believe that He is and that He is a rewarder of those who seek Him.
Paul also reminds us that after coming to faith in Jesus Christ, our life's purpose is to seek to please Him:
2Cor. 5:6 Therefore, being always of good courage, and knowing that while we are at home in the body we are absent from the Lord —
2Cor. 5:7 for we walk by faith, not by sight —
2Cor. 5:8 we are of good courage, I say, and prefer rather to be absent from the body and to be at home with the Lord.
2Cor. 5:9 Therefore we also have as our ambition, whether at home [i.e., alive on earth] or absent [i.e., in Heaven], to be pleasing to Him.
2Cor. 5:10 For we must all appear before the judgment seat of Christ, so that each one may be recompensed for his deeds in the body, according to what he has done, whether good or bad.
For a deeper understanding of these matters, please read the following series of articles:
Will Hell be for eternity for unbelievers?
What does the Bible say about eternal rewards?