"Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent." (John 6:29)
We are called to live a life of faith, not works.
Our works absent the Holy, indwelling presence and power of the Holy Spirit are filth rags:
"But we are all as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away." (Isaiah 64:6)
We in and of ourselves are dirty, unclean, not fit to be in the presence of the Almighty, All Holy God Most High. Our "righteousnesses" (lit. ×¦Ö´×“Ö°×§Ö¹×ªÖµÖ‘×™× ×•Ö¼ tzid·ko·tei·nu — a a manifold plurality of good works ), our attempts to make ourselves clean, with our own means and efforts, only make us more dirty, as well as tired and frustrated with our own exertions.
Jesus has a better way for us:
"Come unto me, all ye that labour and are heavy laden, and I will give you rest.
"Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls.
"For my yoke is easy, and my burden is light." (Matthew 11:28-30)
We must come to Him in faith. We come to faith in God the Father through His Son Jesus Christ, for faith in ourselves, or even faith in faith will not accomplish anything.
When Jesus addresses His hearers who labor, he indicates those who are beaten, worn out, exhausted. Regarding heavy burdens, Jesus is speaking of those overloaded with the insurmountable burden of the Law, which man cannot fulfil in his own efforts. Jesus excoriated the Pharisees for this:
"For they bind heavy burdens and grievous to be borne, and lay them on men's shoulders; but they themselves will not move them with one of their fingers." (Matthew 23:4)
When Jesus offers to us His yoke, He is not asking us to die on the Cross with Him. That is a death, a sacrifice which only he could accomplish. Rather, He is inviting us to be led by the same power — the Holy Spirit:
"And Jesus being full of the Holy Ghost returned from Jordan, and was led by the Spirit into the wilderness." (Luke 4:1)
We all can be led by the Spirit, of course:
"For as many as are led by the Spirit of God, they are the sons of God." (Romans 8:14)
and
"But if ye be led of the Spirit, ye are not under the law." (Galatians 5:1)
In the Holy Spirit, we find rest for our souls:
"Let us labour therefore to enter into that rest, lest any man fall after the same example of unbelief." (Hebrews 4:11)
And notice how the writer of Hebrews points out the cause of falling from this unrest: unbelief.
By faith, therefore, in the Word of God, being led by the Holy Spirit, we can do all things.
We believe on Him, His Holy Spirit is conceived in us, and He achieves all things through us. What blessed reprieve from grief and toil; what blessed relief for every sinner who lets Christ dwell in him by faith.