And if children - If adopted into his family.
Then heirs - That is, he will treat us as sons. An heir is one who succeeds to an estate. The meaning here is, that if we sustain the relation of sons to God, that we shall be treated as such, and admitted to share his favors. An adopted son comes in for a part of the inheritance, Numbers 27.
Heirs of God - This expression means that we shall be partakers of that inheritance which God confers on his people. That inheritance is his favor here, and eternal life hereafter. This is an honor infinitely higher than to be heir to the most princely earthly inheritance; or than to be the adopted son of the most magnificent earthly monarch.
And joint heirs with Christ - Christ is by eminence the “Son of God.” As such, he is heir to the full honors and glory of heaven. Christians are united to him; they are his friends; and they are thus represented as destined to partake with him of his glory. They are the sons of God in a different sense from what he is; he by his nature and high relation, they by adoption; but still the idea of sonship exists in both; and hence, both will partake in the glories of the eternal inheritance; compare Philippians 2:8-9; Hebrews 2:9-10. The connection between Christ and Christians is often referred to in the New Testament. The fact that they are united here is often alleged as a reason why they will be in glory, John 14:19, “Because I live, ye shall live also,” 2 Timothy 2:11-12; “For if we be dead with him, we shall also live with him; if we suffer, we shall also reign with him, Revelation 3:21; “To him that overcometh will I grant to sit with me in my throne,” etc., John 17:22-24.
If so be - If this condition exist; We shall not be treated as co-heirs with him, unless we here give evidence that we are united to him.
That we suffer with him - Greek, “If we suffer together, that we may also be glorified together.” If we suffer in his cause; bear afflictions as he did; are persecuted and tried for the same thing; and thus show that we are united to him. It does not mean that we suffer to the same extent that he did, but we may imitate him in the kind of our sufferings, and in the spirit with which they are borne; and thus show that we are united to him.
That we may be also glorified together - If united in the same kind of sufferings, there is propriety in being united in destiny beyond the scenes of all suffering, the kingdom of blessedness and love.