Romans 14:17 For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost.

The kingdom of God is defined in three terms
1. Righteousness as opposed to sin
2. Peace, the peace of the freedom from sin and its condemnation
3. Joy in the Holy Ghost.

This is the kingdom of Light, the kingdom of the dear son of God, Jesus christ.

Colossians 1:13 Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son:

If you are not in the Kingdom of christ then you are under the power of darkness.

Darkness here means sin, rebellion against God, enmity with God, the devil

Jesus is the only one who can bring one out of the control of the power.
How can I be free from the power of Satan, sin and death?

Romans 10:9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.

You have to confess Jesus the messiah and Lord and believe that God rise him up accepting him as your Lord and saviour.
And afterward continue in his way.

The kingdom of Jesus the messiah is one of righteousness and joy in the Holy Ghost.

True