The rest of Christians is attained by faith.
Hebrews 4:1 Let us fear therefore lest, the promise being left of entering into his rest, any of you should be thought to be wanting. Hebrews 4:2 For unto us also it hath been declared in like manner as unto them. But the word of hearing did not profit them, not being mixed with faith of those things they heard. Hebrews 4:3 For we, who have believed, shall enter into rest; as he said: As I have sworn in my wrath: If they shall enter into my rest; and this indeed when the works from the foundation of the world were finished. Hebrews 4:4 For in a certain place he spoke of the seventh day thus: And God rested the seventh day from all his works. Hebrews 4:5 And in this place again: If they shall enter into my rest. Hebrews 4:6 Seeing then it remaineth that some are to enter into it, and they to whom it was first preached did not enter because of unbelief: Hebrews 4:7 Again he limiteth a certain day, saying in David; To day, after so long a time as it is above said: To day if you shall hear his voice, harden not your hearts. Hebrews 4:8 For if Jesus had given them rest he would never have afterwards spoken of another day. Hebrews 4:9 There remaineth therefore a day of rest for the people of God. Hebrews 4:10 For he that is entered into his rest, the same also hath rested from his works, as God did from his. Hebrews 4:11 Let us hasten therefore to enter into that rest: lest any man fall into the same example of unbelief.
The power of God's Word.
Hebrews 4:12 For the word of God is living and effectual and more piercing than any two edged sword; and reaching unto the division of the soul and the spirit, of the joints also and the marrow: and is a discerner of the thoughts and intents of the heart. Hebrews 4:13 Neither is there any creature invisible in his sight: but all things are naked and open to his eyes, to whom our speech is.
By our high priest Jesus the Son of God, subject to infirmities, but not sin,
Hebrews 4:14 Having therefore a great high priest that hath passed into the heavens, Jesus the Son of God: let us hold fast our confession. Hebrews 4:15 For we have not a high priest who cannot have compassion on our infirmities: but one tempted in all things like as we are, without sin.
we must and may go boldly to the throne of grace.
Hebrews 4:16 Let us go therefore with confidence to the throne of grace: that we may obtain mercy and find grace in seasonable aid.