Aineo , the couple of verses you mentioned above as being the only verses you find in the bible are not all the verses in regard to how important our Faith in Christ is to communion.
To be exact in the King James version there are 220 which I wont paste but here are some of the 220
John.15
[10] If ye keep my commandments, ye shall abide in my love; even as I have kept my Father's commandments, and abide in his love.
Acts.1
[2] Until the day in which he was taken up, after that he through the Holy Ghost had given commandments unto the apostles whom he had chosen:
1Cor.7
[19] Circumcision is nothing, and uncircumcision is nothing, but the keeping of the commandments of God.
1Cor.14
[37] If any man think himself to be a prophet, or spiritual, let him acknowledge that the things that I write unto you are the commandments of the Lord.
Eph.2
[15] Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
Col.2
[22] Which all are to perish with the using after the commandments and doctrines of men?
Col.4
[10] Aristarchus my fellowprisoner saluteth you, and Marcus, sister's son to Barnabas, (touching whom ye received commandments: if he come unto you, receive him
1Thes.4
[2] For ye know what commandments we gave you by the Lord Jesus.
Tit.1
[14] Not giving heed to Jewish fables, and commandments of men, that turn from the truth.
1John.2
[3] And hereby we do know that we know him, if we keep his commandments.
[4] He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
1John.3
[22] And whatsoever we ask, we receive of him, because we keep his commandments, and do those things that are pleasing in his sight.
[24] And he that keepeth his commandments dwelleth in him, and he in him. And hereby we know that he abideth in us, by the Spirit which he hath given us.
1John.5
[2] By this we know that we love the children of God, when we love God, and keep his commandments.
[3] For this is the love of God, that we keep his commandments: and his commandments are not grievous.
2John.1
[6] And this is love, that we walk after his commandments. This is the commandment, That, as ye have heard from the beginning, ye should walk in it.
Rev.12
[17] And the dragon was wroth with the woman, and went to make war with the remnant of her seed, which keep the commandments of God, and have the testimony of Jesus Christ.
Rev.14
[12] Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus.
Rev.22
[14] Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city.
Zeke