Why Is it Even Necessary to Know God?
No person would go out of their way to try to know or understand someone unless there is a compelling reason or need to do so.
So then, why should busy, self-sufficient, modern-day people who are making all the money in the world stop and try to know someone as divest of mortal material or substance as God?
Considering the odds
There are only two scenarios: either it is necessary to know God or it is not necessary (or even impossible) to know God.
The latter is simple. If you share this belief, you are saying, "I am my own boss, I determine my own destiny. Life is short, death is certain, but how I live it is totally my business."
"Since I won't be able to carry my possessions when I die, I just need to be a 'good' person, enjoy as much as I can, live a good life until I die... and that's it."
On the other hand, I'm acknowledging that we need to get to know God personally, and that God is our Creator. He made us in His own image. He has a marvelous plan for our lives, and wishes that our committed relationship with Him will give us happiness here on earth, and consummate in eternal life, joy, and peace forevermore when He returns according to the Bible (1 Thessalonians 4:16-18, Revelation 1:7).
Well, if you invest money in the stock market or other entity where you can expect some return on your investment, you know what it means to consider the odds.
Let's say, that each proposition has a 50% chance of being true. After all, we have to be fair. You have never visited every single square foot of space in the universe and proved that there is no heaven. And I can only go by what the Bible says.
Now, let's say we both lived our lives the ways we think - you not acknowledging God and I, making Him my personal Friend and Guide. You have another idea of what will happen to mankind eventually, and I believing in the Bible's prediction of a final everlasting kingdom, believe that Jesus will come again as He said He would - then...
If one final day your theory proves to be right, I would have lived a happy Christian life and you a happy non-Christian life. We both would have lived life the way we thought best.
We could join Frank Sinatra and say, "I did it my way!" But...
If one final day we see the Bible's prophetic declaration appearing as a strange cloud in the skies, we hear angels singing, and we see some people running while another group is in glorious ecstasy looking to the skies. If on that judgment day we see that I am right, then one of us would be eternally sorry.
Now you could see why we need to know God as he encourages us to do - it is a better risk to take even if the "odds" are less than fifty-fifty.
What the Bible Says
The Bible says, that we have inherited a sinful nature (Romans 3:23). It says that God loves us (John 3:16), and does not want us to suffer the eternal punishment for sin.
"The Lord is not slow in keeping his promise, as some understand slowness. He is patient with you, not wanting anyone to perish, but everyone to come to repentance." - 2 peter 3:9
He is even patient in waiting for us to come to know Him. He does not want us to suffer sin's final destructive wages:
"For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord." - Romans 6:23
So God encourages us to get to know Him. He encourages us to seek Him out.
"You will seek me and find me when you seek me with all your heart." - Jeremiah 29:13
Why do we need to know God? Because eternal life necessitates it. You can get to know now, and that's heaven's hope for you, my friend.