Which gave them me - See John 6:37.
Is greater - Is more powerful.
Than all - Than all others - men, angels, devils. The word includes everything - everything that could attempt to pluck them away from God; in other words, it means that God is supreme. It implies, further, that God will keep them, and will so control all other beings and things that they shall be safe.
None is able - None has power to do it. In these two verses we are taught the following important truths:
1. that Christians are given by God the Father to Christ.
2. that Jesus gives to them eternal life, or procures by his death and intercession, and imparts to them by his Spirit, that religion which shall result in eternal life.
3. that both the Father and the Son are pledged to keep them so that they shall never fall away and perish. It would be impossible for any language to teach more explicitly that the saints will persevere.
4. that there is no power in man or devils to defeat the purpose of the Redeemer to save his people. We also see our safety, if we truly, humbly, cordially, and daily commit ourselves to God the Saviour. In no other way can we have evidence that we are his people than by such a persevering resignation of ourselves to him, to obey his law, and to follow him through evil report or good report. If we do that we are safe. If we do not that we have no evidence of piety, and are not, cannot be safe.

My Father - is greater than all - More powerful than all the united energies of men and demons. He who loves God must be happy; and he who fears him need fear nothing on this side eternity.

My Father which gave them me,.... So the sheep came to be Christ's, and to be in his hand; the Father gave them to him, put them into his hands, and made them his care and charge:
is greater than all; than all gods, than all beings, than all creatures, angels and men, and than all the enemies of his people; this must be allowed: the Vulgate Latin version, and so some of the ancients read, "what my Father gave to me, is greater than all"; meaning, that the church given to him, and built on him, is stronger than all its enemies:
and none is able to pluck them out of my Father's hand; so that these sheep have a double security; they are in the hands of Christ, and they are in the hands of the Father of Christ; wherefore could it be thought, which ought not to be, that they could be plucked out of Christ's hands, yet it can never be imagined, that any can pluck them out of the hands of God the Father; and there is no more reason to think that they can be plucked out of the hands of the one, than there is that they can be plucked out of the hands of the other, as is clear from what follows in John 10:30; see the Apocrypha:
"But the souls of the righteous are in the hand of God, and there shall no torment touch them.'' (Wisdom 3:1).

My Father, which gave them me--(See on John 6:37-39).
is greater than all--with whom no adverse power can contend. It is a general expression of an admitted truth, and what follows shows for what purpose it was uttered, "and none is able to pluck them out of My Father's hand." The impossibility of true believers being lost, in the midst of all the temptations which they may encounter, does not consist in their fidelity and decision, but is founded upon the power of God. Here the doctrine of predestination is presented in its sublime and sacred aspect; there is a predestination of the holy, which is taught from one end of the Scriptures to the other; not, indeed, of such a nature that an "irresistible grace" compels the opposing will of man (of course not), but so that that will of man which receives and loves the commands of God is produced only by God's grace (OLSHAUSEN--a testimony all the more valuable, being given in spite of Lutheran prejudice).

No man is able to pluck them out of my Father's hand. The sheep who hear his voice and follow him (John 10:27). This is the condition of their safety. If they comply with it God's grace will save them from the adversary.