John was accepted witness for Christ, and this is proved by three things which were accomplished by John. The first thing pertains to the condition of nature, namely, “John was a light.” The second pertains to the perfection of his love, because John was “a burning light.” The third refers to the perfection of his intellect, for “John was a shining light.”

1. John was perfect in nature for he was a light, that is, he was illuminated by grace, and illuminated by the light of God’s Word. The light (in John) differed from ordinary light, for ordinary light is that which shines by its own power; but this light in John was a participation of the Divine Light. For according to John 1:9, “The true light that enlightens every man was coming into the world.” John, however, was not the “the Light,” but a light, for he was enlightened “He was not the light, but came to bear witness to the light (John 1:8) and be led to Christ. It is written of the light which shone in John: “I have prepared a lamp for Christ, my anointed (One). (Ps. 131:7).
2. Likewise the love that was in John “was burning and shining.” For there are some lights that shine only in regard to duty but are extinct in regard to love (of God). For just as light or a lamp cannot shine unless it is first enkindled and inflamed by the fire of charity. And hence the flame of love shines forth to enlighten because through the burning flame of charity the knowledge of truth is communicated. “No longer do I call you servants, or the servantdoes not know what his master is doing; but I have called you friends, for all that I have heard from my Father I have made known to you” (John 15:15). And again: “So I turned about and gave my heart up to despair over all the toil of my labors under the sun” (Eccl’us 2:20). Fire has two qualities, namely, it burns and shines. But the heat from fire represents love by of reason of three things:

First of all because among all things material fire is the most active, and likewise with the flame of charity, for nothing resist its power. “For the love of Christ controls us, because we are convinced that one has died for all; therefore all have died” (2 Cor. 5:14).

Secondly, just as fire is made to burn much from the fact that it is especially sensitive (and rapidly spreads) so also, charity produces the warmth of fervour (and burns away the dross of earth) so that man might pursue the ways of God and follow his destined course unto the end.

Thirdly, just as fire is led upwards, so also charity, inasmuch as it unites us with God. “So we know and believe the love God has for us. God is love, and he who abides in love abides in God, and God abides in him” (1 John 4:16).

3. John was shining in intellect.

First, interiorly by a knowledge of truth for “the Lord filled his soul with brightness,” (Isaiah 58:3, 2)., that is, He made, He caused John to shine with heaven’s splendor.

Secondly, John shone exteriorly by his preaching the word of God. “that you may be blameless and innocent, children of God without blemish in the midst of a crooked and perverse generation, among whom you shine as lights in the world’ (Phil 2:15).

Thirdly, John was shining light by the examples of his good works. “Let your light so shine before men, that they may see your good works and give glory to your Father who is in heaven” (Matt. 5:16).