Why ask God for anything if He already knows what U need? (Mat 6:8)

You are to ask God in prayer for the following reasons: 

1. To exercise and develop personal faith in God (Mar 11:22-24)

2. To prove God's promises true: 2Co 1:20  All the promises of God in him are yes and amen to the glory of God by us.

3. To bring glory to God: Joh 14:13  Ask in my Name....that the Father may be glorified in the Son.

4. To show you depend on the Lord, not yourself or man: Psa 118:8 It is better to trust in the Lord Than to put confidence in man.

5. To demonstrate God's ability to provide for you: Phi 4:19 My God shall supply all your need.

6. To show God’s goodness to all men: Jam 1:17 Every good gift and every perfect gift is from above. Rom 2:4 Goodness of God leads you to repentance.

7. To bring fullness of joy: Joh 16:24  Ask and receive that your joy may be full.