When Jesus said he'd finished, he had overcame Satan. He denied himself unto his last breath and Satan couldn't get him to sin, no matter what he did. Satan would have loved nothing better than for Jesus to go against God. He tempted him in the wilderness to do so. And he was doing it at the cross too. Satan was going to make Jesus suffer and God foreknew what Satan would do to Jesus and Jesus was willing for it to bare witness to the truth hoping to save as many as would believe in him and in the gospel. And then live by it, and through Christ, bare witness to the truth themselves.
Jesus could have turned away at anytime, he could have said anything to please them to get them to stop, but he didn't as he had to suffer whatever was set before him and if he turned away then wouldn't have been speaking or baring witness to the truth. So he had to suffer what he went through, he had to suffer whatever Satan did to him and overcome him and not give in to his temptations and not go against God. Satan had wicked men scourge and beat Jesus and murder him and put him through immense suffering to try and get him to sin and turn from God. But Jesus was too strong for him, God has sent an angel to strengthen him because he was always living by the will of God so God never left him, he was with him always strengthening and giving him the power over all flesh and power over Satan and giving him the strength to bare everything he was going through and overcome Satan right until his last breath. Then he had finished, he fought Satan on his own ground and won!
And now Christ through the Spirit can strengthen us to overcome too, the life of Christ in our hearts should be helping us to stop sinning, the power of the Spirit should be helping us to overcome.
Would Christ be telling us to sin? No, he will be teaching and guiding us to turn from sin, when we know it's a sin to do something and do it, then we are listening to the devil, the prince of this world who wants to keep us in darkness and away from the light of Christ. And he does that by tempting us to sin but if we have Christ in our hearts, then we should be able to know that the devil is tempting us and we should turn away, and if it's hard to do, then we are to go to God and pray hard for help in the name of Jesus Christ and have complete faith in him, trust in him and that he can do anything. God can help us to overcome anything in this world. He is a living God, and all things are possible with him. If he is on our hearts, then he is stronger than he who is in the world and he can help us to overcome the devil and his sinful ways.