In 1563 two young men, at the request of Elector Frederick III and with the advice of the entire theological faculty of the local university, wrote one of the simplest, most profound, and most comforting passages to come out of the great reformation.
Here it is, Question and Answer 1 of the Heidelberg Catechism.
Q. What is your only comfort in life and death?
A. That I am not my own, 
but belong with body and soul,
both in life and in death, 
to my faithful Saviour Jesus Christ.
He has fully paid for all my sins
with His precious blood,
and has set me free from all the power of the devil.
He also preserves me in such a way
that without the will of my heavenly Father
not a hair can fall from my head;
indeed, all things must work together
for my salvation.
Therefore, by His Holy Spirit
He also assures me of eternal life
and makes me heartily willing and ready
from now on to live for Him.
 I Cor. 6:19, 20
 Rom. 14:7-9.
 I Cor. 3:23; Tit. 2:14.
 I Pet. 1:18, 19; I John 1:7; 2:2.
 John 8:34-36; Heb. 2:14, 15; I John 3:8.
 John 6:39, 40; 10:27-30; II Thess. 3:3; I Pet. 1:5.
 Matt. 10:29-31; Luke 21:16-18.
 Rom. 8:28.
 Rom. 8:15, 16; II Cor. 1:21, 22; 5:5; Eph. 1:13, 14.
 Rom. 8:14.
This question and answer is copied from the webpage of the Kelmscott Free Reformed Church of Australia.