Jesus, knowing that the Father had given all things into his hands, and that he had come from God and was going back to God, rose from supper. He laid aside his outer garments, and taking a towel, tied it around his waist . . .
When he had washed their feet and put on his outer garments and resumed his place, he said to them, â€œDo you understand what I have done to you? You call me Teacher and Lord, and you are right, for so I am. If I then, your Lord and Teacher, have washed your feet, you also ought to wash one another's feet. For I have given you an example, that you also should do just as I have done to you. Truly, truly, I say to you, a servant is not greater than his master, nor is a messenger greater than the one who sent him. If you know these things, blessed are you if you do them.â€ John 13:3-4, 12-17, ESV
This passage contains one of the very few instances in the New Testament wherein Jesus is set forth as an example after which believers are to pattern their behavior. Historically, a major problem in the Church has been the reduction of Christianity to the question, "What would Jesus do?" If we can just imagine how Jesus would behave in specific situations, we can mimic himâ€”no problemâ€”and live better lives... right?
"If you know these things, blessed are you if you do them." We are commanded to imitate Jesus, and promised that we will be happy if we do. But we do have a problem: how do we imitate him genuinely? God doesn't just want our external behavior to conform to the behavior of his Son (i.e. footwashing or service)â€”he wants our hearts to conform to his Son's heart. Since the motivations of our hearts dictate the course of our actions, we need to know how to imitate Jesus in the fullest possible sense. That is, we need to know how to be motivated the same way.
In this passage we have both Jesus' behavior and his motivation. The behavior is obvious: he astonishingly humbles himself in service. The motivation is a little less obvious, but powerful: "Jesus, knowing that the Father had given all things into his hands, and that he had come from God and was going back to God, rose from supper" (emphasis mine).
Jesus had the full assurance of his Father's favor upon himâ€”as the Son of God, he was Heir of All Things, and he experienced especially the fullness of eternal Triune relationality. With this in his heart and mind, he was able to give completely of himself, even to the point of death. Our motivation for humble service after his example can be nothing else, or else it will not be true imitation of our Lord and Savior. If we do not give of ourselves out of the fullness of right relationship with God, we do not imitate or honor Christ, even if our acts might seem selfless like his.
So how do we get this assurance, that God's favor is upon us as it is upon his only begotten Son? By being found in Christ by faith. The full and glorious favor of the Father rests forever upon those who are in the Son by faith. We are co-inheritors of All Things with our Elder Brother, Jesus, because we are in him by faith. We are brought into the blessed fellowship of the Trinity as we are in the Second Person by faith. There is no other way to have the full assurance of these things than to be in Christ by faith.
The one who is thus assured has nothing to lose by giving completely of himself, even to the point of death. In fact, there is much joy to gain in the participation of the work of Christ on earth as we imitate him in every way.