Jesus ultimately saves but he does have his requirements before saving you into the kingdom of heaven.
Was His salvation then insufficient?
The Bible teaches that not everyone will enter into the kingdom of heaven. Why? Because you have to be righteous to live in the kingdom of heaven. Jesus' atonement was plenty sufficient to save all mankind from death and all will be resurrected. It was also sufficient to save all mankind into the kingdom of heaven based upon the principle of repentance.
17 From that time Jesus began to preach, and to say,
Repent: for the kingdom of heaven is at hand.
Jesus was clear on the doctrine of repentance that if we don't repent we will all likewise perish:
Luke 13:1-5
1 There were present at that season some that told him of the Galilæans, whose blood Pilate had mingled with their sacrifices.
2 And Jesus answering said unto them, Suppose ye that these Galilæans were sinners above all the Galilæans, because they suffered such things?
3 I tell you, Nay: but, except ye repent, ye shall all likewise perish.
4 Or those eighteen, upon whom the tower in Siloam fell, and slew them, think ye that they were sinners above all men that dwelt in Jerusalem?
5 I tell you, Nay: but, except ye repent, ye shall all likewise perish.
Repentance is one of the first principles of the gospel of Jesus Christ. If we don't repent, Jesus tells us that we shall all perish. Jesus is not just a merciful God, but a just God as well. He cannot allow the unrepentant sinner into the kingdom of heaven. For this reason he taught us to repent in order to obtain the kingdom of heaven. Only the just will find their way to the kingdom of heaven. Those who are wicked will not. What does it mean to repent? It means to stop sinning and keep the commandments of God. It is true that no matter how much we repent and keep the commandments of God, without the atoning sacrifice of Jesus Christ those actions will avail us nothing. But that doesn't mean that we inherit the kingdom of heaven without doing anything.
Jesus requires us to repent before he will grant the mercy to allow us into the kingdom of heaven. Do you suppose that the wicked will inherit the kingdom of heaven? No! They won't because they are unwilling to repent and come unto Jesus so that he can save them. Does this make Jesus' atoning sacrifice insufficient? It has always been insufficient to save the wicked and godless into the kingdom of heaven. Why? Because God is a just God and can only allow those who repent and change their life into a good being. Only the just will inherit the kingdom of heaven. Without the atoning sacrifice of Jesus, no man would rise from the grave. All mankind will rise and be resurrected because of Jesus. However, not all will enter the kingdom of heaven because they are required to repent and change from being evil to being a good being.
Through repentance, the atonement of Jesus Christ can save us into his kingdom. Otherwise we need to be placed elsewhere. Repentance and good works in and of themselves cannot save us. We need the atoning blood of Jesus to be saved. However, Jesus cannot save the wicked into his kingdom unless they repent. Heaven would not be heaven with the unrepentant wicked doing what they do there. For this reason, those who do not repent will be sent elsewhere and will not inherit the kingdom of heaven. It would be unjust for Jesus too allow the wicked into heaven. For this reason, repentance is a requirement of Jesus before he will allow us into his kingdom.
Jesus does not save all into the kingdom of heaven. The difference is whether they repent and follow after him. I don't believe that a person is first saved into the kingdom of heaven before repenting. Nowhere in the Bible does it teach that. Repentance comes before one is saved into His kingdom. And that is what we will be judged upon before it is determined if we are allowed into the kingdom or not.