Psalm 37:4
Delight yourself in the LORD and he will give you the desires of your heart.

In finding out God's purpose for your life, you have to delight yourself
in Him first.

What does that mean?

Follow up:

That first you have to know Him... That you should seek God if you don't
already know Him...

"You must wager; it is not optional... Let us weigh the gain and the loss
in wagering that God exists... If you gain, you gain all; if you lose, you
lose nothing. Wager, then, without hesitation, that He exists." - Blaise Pascal

Matthew 7:8
For everyone who asks receives; he who seeks finds; and to him who knocks,
the door will be opened.

Jeremiah 29:13
You will seek me and find me when you seek me with all your heart.

Psalm 119:2
Blessed are they who keep his statutes
       and seek him with all their heart.

Then to 'delight yourself' you have to realize that He is good and loves
you as His child...

John 3:16
For God so loved the world that he gave his one and only Son, that whoever
believes in him shall not perish but have eternal life.

Romans 8:28
And we know that in all things God works for the good of those who love
him, who have been called according to his purpose.

Proverbs 23:18
There is surely a future hope for you, and your hope will not be cut off.

When you have accepted Christ and His promises, you have to align your
heart with God's goals...

Galatians 5:13-14
You, my brothers, were called to be free. But do not use your freedom to
indulge the sinful nature; rather, serve one another in love. The entire
law is summed up in a single command: "Love your neighbor as yourself."

Galatians 5:22-24
But the fruit of the Spirit is love, joy, peace, patience, kindness,
goodness, faithfulness, gentleness and self-control. Against such things
there is no law. Those who belong to Christ Jesus have crucified the
sinful nature with its passions and desires.

When you know God and know that He is good, it is easy to follow the
desires He puts in your heart, and you will find that they are fulfilling!

Joshua 21:45
Not one of all the LORD's good promises to the house of Israel failed;
every one was fulfilled.

Proverbs 13:25
The righteous eat to their hearts' content, but the stomach of the wicked
goes hungry.

Sometimes you may find that your purpose is a little "out-of-the box", and
if so, consider this:

Romans 12:2
Do not conform any longer to the pattern of this world, but be transformed
by the renewing of your mind. Then you will be able to test and approve
what God's will is—his good, pleasing and perfect will.

You will also find that God has given you tools to achieve His purpose and
that He will be with you always...

2 Timothy 3:16-17
All Scripture is God-breathed and is useful for teaching, rebuking,
correcting and training in righteousness, so that the man (or woman) of
God may be thoroughly equipped for every good work.

Joshua 1:9
Have I not commanded you? Be strong and courageous. Do not be terrified;
do not be discouraged, for the LORD your God will be with you wherever you
go.

I pray that you may find God, His love for you, and your God-given purpose...