18 For this is what the LORD says, [He] who created the heavens (He is the God who formed the earth and made it, He established it [and] did not create it as a waste place, [but] formed it to be inhabited): "I am the LORD, and there is no one else. [Isa 45:18, NASB20]

This is but one God, one who created the heavens and formed the earth. The God that created the world and made it to be a dwelling place for man. How great is our God!  

15 So, for my part, I am eager to preach the gospel to you also who are in Rome.

16 For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek.

(Romans 1:15-16, NASB)

Paul was not ashamed of the Gospel because this good news is God’s power, the purpose and goal of which is to bring about deliverance or salvation. A man obtains such salvation when his response to the Gospel is trust and belief.

14 After He called the crowd to Him again, He [began] saying to them, "Listen to Me, all of you, and understand:

15 there is nothing outside the person which can defile him if it goes into him; but the things which come out of the person are what defile the person."

16  ["If anyone has ears to hear, let him hear."]

17 And when He [later] entered a house, away from the crowd, His disciples asked Him about the parable.

18 And He said to them, "Are you so lacking in understanding as well? Do you not understand that whatever goes into the person from outside cannot defile him,

19 because it does not go into his heart, but into his stomach, and is eliminated?" ([Thereby] He declared all foods clean.)

20 And He was saying, "That which comes out of the person, that [is what] defiles the person.

21 "For from within, out of the hearts of people, come the evil thoughts, [acts of] sexual immorality, thefts, murders, [acts of] adultery,

22 deeds of greed, wickedness, deceit, indecent behavior, envy, slander, pride, [and] foolishness.

23 "All these evil things come from within and defile the person." (Mark 7:14-23)

Jesus is responding to the question about following the customs and traditions of washing your hands carefully before eating. He is pointing out that it is our wicked thoughts and affections, words and actions, that defile us, and these only, not the food they were referencing in the question. Where a corrupt fountain sends forth corrupt streams, so does a corrupt heart send forth corrupt reasonings, corrupt appetites and passions, and all the wicked words and actions that come from them.

We need to ensure that we do not lean on customs and traditions set forth by mankind, instead, we need to place our Heartfelt faith in God. What we feed our Hearts is what is important. Feed your Heart the word of God.

5 This is what the LORD says: "Cursed is the man who trusts in mankind And makes flesh his strength, And whose heart turns away from the LORD.

6 "For he will be like a bush in the desert, And will not see when prosperity comes, But will live in stony wastes in the wilderness, A land of salt that is not inhabited.

7 "Blessed is the man who trusts in the LORD, And whose trust is the LORD.

8 "For he will be like a tree planted by the water That extends its roots by a stream, And does not fear when the heat comes; But its leaves will be green, And it will not be anxious in a year of drought, Nor cease to yield fruit.

9 "The heart is more deceitful than all else And is desperately sick; Who can understand it?

10 "I, the LORD, search the heart, I test the mind, To give to each person according to his ways, According to the results of his deeds. (Jeremiah 17:5-10)

Jeremiah contrasts those who place their Heartfelt Faith in mankind, and think they can do without God, which leads to evil and corruption, versus those who make God their Hope, placing their Heartfelt Faith in God, and how they will flourish. Those who center their Faith on God (Heartfelt Faith), shall not cease yielding fruit in holiness and good works.

10 for with the heart [a person] believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation. (Romans 10:10)

Paul points out that it is with the heart that a person believes unto righteousness. Salvation is not merely based on a whim or an intellectual exercise. Salvation must rest on a genuine, bona fide heartfelt faith in God and His Son, Jesus Christ Who was sent by the Father to be “the” sacrifice for the sin of the whole world. "Believe on the Lord Jesus Christ, and you will be saved," Paul told the Philippian jailer - for God gave His only begotten Son into the world "that whosoever believes on Him shall be saved."