There are different ways to explain this.
- Jesus said (Matthew 22:34-40) that the laws of Moses are summed up as to love the Lord with all the heart, soul, mind, and strength, and to love your neighbor as yourself. It will take time to be brought to that place because we have learned to love other things or hold onto cultural traditions, or learned biases, that prevent us from loving God as we ought to. So giving up all for the sake of Christ will mean giving up whatever keeps us from loving God supremely.
- In Matthew 10:32-39, we see how devoted Jesus expects His followers to be to Him. They are not to deny Him when the going gets tough. When they set out to work for Jesus, their family members must not get in the way. They need to bear their own cross, saying no to themselves so they could follow Jesus’ commands. Any missionary could tell you how hard it was when they set out to obey Jesus, and how much it disrupted their lives–and also how they would not have it any other way.
So giving up all for the sake of Christ means to make sure nothing in your life is keeping you from following Jesus. In a practical way, you stay in the Word of God morning and night, and when you understand what it is telling you to do, you make adjustments in your life so you can respond to it in faith. This you keep doing day by day, giving up whatever it is that keeps you from obeying. You don’t give up stuff on your own; you let the Spirit guide you to do that. The Scriptures will show you what you must give up; it will be different for everyone.
Jesus modeled this life. He gave up all for the Father so that He could do the Father’s will. In John 5:30, Jesus says that He does not seek His own will. He does what the Father tells Him to do. This is our goal–to be at the Lord’s service in whatever way He needs us.
