1 witness of Christ here, and 1 further echo from the reading.
And it came to pass, that on the other hand, the people of Nephi did thank the Lord their God, because of his matchless power in delivering them from the hands of their enemies. Alma 49:28
The Lord their God who delivers His covenant people is Jehovah, the premortal Christ. The Nephites credit His matchless power, not their fortifications alone, for their deliverance.
How we know: Jehovah is the premortal Christ (Abraham 1:16; D&C 110:3–4)
Yea, and there was continual peace among them, and exceedingly great prosperity in the church because of their heed and diligence which they gave unto the word of God, which was declared unto them by Helaman, and Shiblon, and Corianton, and Ammon and his brethren, yea, and by all those who had been ordained by the holy order of God, being baptized unto repentance, and sent forth to preach among the people. Alma 49:30
The 'holy order of God' is the high priesthood, which Alma taught is 'after the order of his Son' and which modern revelation calls the Holy Priesthood after the Order of the Son of God. The preachers carry authority that bears Christ's pattern and points people to His redemption.